64 bits…when?

I’ve gotten a number of questions on the beta forums as to why Photoshop CS3 won’t have a 64-bit version.  It’s definitely a when question, not an if, and there are a lot of factors involved.  I though I might collect some of the information together here.

First, let’s check all the 64-bit hype at the door.  Being a 64-bit program means, most simply, that pointers in an application are 64 bits wide, not 32 bits.  A 32 bit pointer means that an application can address 2 ^ 32 bytes of memory, or 4GB, at the most.  The operating system an application runs on slices that application address space up, so that the application can actually only allocate a part of that address space for itself.  Thus, on Windows XP, an application can use 2GB of address space, on Macintosh OS X 10.4, an application gets 3GB, on Windows XP 64-bit edition, a 32-bit application gets nearly 4GB of address space.  Applications don’t allocate RAM on most modern operating systems – that’s a common misconception and a gross oversimplification your computer geek friends tell you because they don’t want to explain virtual memory, TLBs and the like.

A 64-bit application doesn’t have same that limit on its address space, since pointers are 64 bits – they can address a much larger amount of memory.  That’s pretty much it.  64-bit applications don’t magically get faster access to memory, or any of the other key things that would help most applications perform better.  Yes, the x64 instruction set has some more registers available, and that helps in limited circumstances, but the processing throughput of a memory bandwidth bound application is pretty much not going to benefit from being a 64-bit application.  In fact, it gets worse in many cases because the internal data structures the application is dealing with get bigger (since many data structures contain pointers, and pointers in a 64-bit application are twice as big as in a 32-bit application).  Memory bandwidth has not kept up with processor speeds, and has become a precious resource.

Let’s contrast to the old switch from 16-bit to 32-bit computing.  During that switch, 16-bit applications were already not really true 16-bit applications (in order to address 640k of memory, there was a really ugly hack that meant pointers weren’t really pointers and weren’t really 16 bits) – so the data structures an application was dealing with pretty much didn’t change in size at all.  Even if they did, memory bandwidth at that point in history was high enough relative to processor performance that what data structure size increases did happen were easily absorbed and didn’t affect performance significantly.  Not only that, but for many operations, moving to 32-bit computing meant a lot of fixed point math could be done in a lot fewer instructions, and a lot faster.  For many applications, this was such a huge win -and one of the reasons why the switch to 32-bit computing happened fast relative to the 64-bit computing switch.  These days, many 32-bit processors already have math instructions for doing 64-bit fixed point math to the degree most applications need it, and many things are done in floating point.  Combine the performance penalty for the data structure size increase with the lack of any sort of other performance win, and the number of situations in which an application being 64-bit are a performance win is very small.

And, in the cases where it would be a win – dealing with a very large data set (Photoshop files over 1GB is a good guess as to about where things get interesting) – having the operating system use any unused RAM to cache scratch disk reads and writes can be nearly as effective (depending on how good the operating system is at this – and there are even a few add-on products which can make it even better) as having Photoshop itself being able to hold all of scratch within it’s own address space.  (Side note: a computer system is most efficient when it has nearly no free RAM – there really is no point in having RAM sit empty.  An aggressive file cache is one good way of accomplishing this.  Vista is supposed to be really good at this, but I don’t have enough direct experience yet to know for sure.)

Ok, so in a very limited set of cases there might be a little bit of a win for Photoshop to be a 64-bit application.  But…

A 64-bit application can’t be run on a 32-bit chip or a 32-bit operating system.  That means a 64-bit version of Photoshop would have to be a completely separate binary from the 32-bit version.  A separate binary has a huge cost associated with it (in terms of features we can’t do because we have to spend resources elsewhere).  Quality assurance is a big part of that – you essentially have to dive in and test every corner of the app for each binary, across the matrix of supported operating systems – but there are also many ancillary pieces that add to that cost as well.  And given that a Universal Binary application really is two separate binaries smashed together (and accounting for the kinds of issues that an application can have going from big endian (PPC) to little endian) we already had a lot of extra cost going through this cycle.  Adding the cost of adding a 64-bit version to the mix of things that were already on the have-to-do list – especially in light of the very limited benefits – and doing a 64-bit version this cycle really became an unreasonable thing to think about it.

There’s more.  Since a 64-bit application can only run on a 64-bit chip with a 64-bit operating system, just how many users could run a 64-bit version in the first place?  Macintosh OS X 10.4 isn’t fully 64-bit – many of the libraries an application would need to be fully 64-bit aren’t available.  So, on the Macintosh side the answer is zero.  Ok, so consider the Windows side: Windows XP 64-bit edition has been out a bit.  How many Photoshop customers run it?  A vanishingly small percentage – there’s been a lack of compatible drivers, especially for the kinds of things that make up a Photoshop workflow, like scanner divers, monitor calibration bug drivers, and the like. Things are looking better for Vista – it comes with a wider spread of 64-bit drivers out of the box – but there are still 64-bit versions of some of the pieces of the puzzle missing there, and the expected Vista adoption rates mean that the number of Photoshop customers running the 64-bit version of Vista will remain very tiny over the next couple of years.  Yes, there’s a whole look to the future thing, but even considering that, the timing just isn’t right yet.

As for the engineering part of it, well, I want to do it.  I want the transition to 64-bit computing to happen sooner rather than later, I’d really like to not have to worry about address space limitations so much.  Once, long ago, I ported Display PostScript to the Dec Alpha workstations (what a nice processor, sigh…), so I have a good idea of what the level of engineering work will be.

At some point, some of these things will change – certainly the number of systems capable of running a 64-bit version of Photoshop will – and at some point it will make sense to do a 64-bit version.  That wasn’t this time around.  But like I said, it’s a when, not an if.

77 Responses to 64 bits…when?

  1. Rosyna says:

    I wonder how large (file size) a four way fat version of the Creative Suite would be.[Multiply the size of the Universal Binary beta version of the Photoshop .app folder by 2, plus maybe 5-10% as a fudge factor. – Scott]

  2. That’s interesting that Mac OS X has libraries that are not 64bit, but are required by the application. I had the impression it was resistance on Adobe’s part. Thanks for the thorough answer on the 64 bit question.[You’re welcome. I’m pretty sure Apple realized there was little benefit for GUI applications, and they were more after allowing server applications to be 64-bit, where the balance of things is different and access to very large data sets to keep many threads alive is more important than the responsiveness of any single thread. – Scott]

  3. Paul Gardner says:

    What ever you do! Keep the code from ever swapping to disk. Your statement that modern applications don’t allocate memory is a cop-out. Go back to K&R “C” where you can dynamically allocate and free memory. C++ is a bean counter code. When doing a batch in Bridge each image should be freed after processing instead of continually increasing memory usage. The image load time should be much shorter than the swap time. Using photomerge the swap file to a scci swap drive is constantlay threshing. Your graphics are great but your memory management suck.Still I am a faithful PS user even if I bitch a lot.[Nope, not a cop-out at all, but reality. You seem to still be missing a level of understanding about memory. Read the Wikipedia article on it. K&R’s reference to memory doesn’t mean RAM but address space. And, if anything, C++ allows for far better scoping of memory and far less chance of leaks – but the basic allocation mechanisms are the same as in C. Note that the term is thrashing, not threshing – and usually indicates too many applications keeping too much memory active (which is different than allocated) – sometimes a problem with setting the memory percentage too high while running a lot of active apps – use Performance Monitor to see what is actually going on and where the I/O is coming from. Photomerge is a particularly tough plug-in on memory, though, due to the nature of what it is doing. And I think you are still missing how serious a problem address space fragmentation is. – Scott]

  4. Clay White says:

    Scott,You cannot know how important the clear and understandable explanations of these technical issues are to us.As instuctors we always get some heavy tech guys asking questions in an attempt to make us look ignorant.The willingness of Adobe staff to make us smart give me the ammo to look really “all knowing” to the students.Adobe rocks – thanks again.Clay White[No problem. It’s easy to get a dangerous amount of knowledge on this stuff, as I’m sure you’ve found. – Scott]

  5. Dustin Senos says:

    Great read. Informative and to the point. Thank you for shedding some light on the world of wider pointers.Seems dual core processors are all the trend now a days. These appear to offer a chance for large performance increases. Has CS3 been implemented to take advantage of multi cores? Is it still a memory issue before we see full benefits? Can you point us to a document discussing the ways you approached performance increases in CS3?[Photoshop has taken advantage of multiple processors since the very early days, but yes, memory bandwidth prevents us (and any memory bandwidth bound application) from taking full advantage of multiple processors / multiple cores except for limited cases (e.g., Radial Blur is still compute bound). Unfortunately, it’s not something you or I can do much about. The performance topic would be a good one for after the break. – Scott]

  6. Brandon says:

    The paint.net blog had a few instances of 64bit performance increases.http://blogs.msdn.com/rickbrew/archive/2006/02/17/534394.aspxThere are a few apps out there that just benefit from moving from 32bit to 64bit.[Ah, yes, single routines where the 32-bit version of the routine suffered from lack of registers is indeed the birght spot of 64-bit conversion. Note that we did such tests with Photoshop’s versions of such routines, and probably because the Photoshop 32-bit versions have long been optimized to work around the lack of registers and slow 64-bit math, there were no such big wins. – Scott]

  7. Albert says:

    Hi Scott,Leopard will be fully 64bit and everyone will use it one the mac platform (especiallay since 32bits apps can run on it).Moreover, what about CoreGraphic, or the capabilitie to use the GPU to perform the math ?[Yes, Leopard makes 64-bit bit a choice on the Macintosh side as well – if we had tried to do 64-bit this time around, it would had have to have been Windows only. As for the GPU, it’s fast computationally, but the data pipe is mostly one way – getting data back from it once processes is very slow. – Scott]

  8. patrick says:

    Interesting article. I’m not a PS expert, but I believe that PhotoShop has its own an elaborate scratch disk / VM implementation. Does that still offer a benefit on modern operating systems? (you mention the prowess of modern OSes in passing).Related to this, to which degree is the age of the code base holding you back? I assume that most of the code added in the past few years has been written with 64bit in mind, but how much code from the days of the Classic Mac and Win95 is still around? I could imagine you’d want to put off sorting that out if you can avoid it. Then again, it may offer advantages as well (like ‘scratching’ your own VM?).[On Photoshop’s VM, it’s 2D oriented, and uses large tiles, and in some cases we can use it to increase the I/O and CPU usage overlap. When we move 64-bit we will almost certainly keep the VM system since it will still offer significant performance benefits (we’ll test, of course, to be sure). As for the age of the code base, we’re pretty good about keeping it clean, but yes, some of the older code is where the problem in porting to 64-bit might be. But fixing out code up isn’t really that hard, and isn’t where the cost comes from. – Scott]

  9. David Bainbridge says:

    For what its worth, the next version of OS X (10.5) you can have a full 64 bit GUI app, system libraries and all.[Yup, looking forward to it. – Scott]

  10. Albert says:

    For the GPU acceleration, you says getting the data back is slow, but Apple’s fun house that display PS like filters in real time seems fast to me.[That data is only going one way – to the display. – Scott]

  11. Saul says:

    It’s too bad that Adobe hasn’t embraced 64 bit yet, but as of now Photoshop CS2 has some support for 64 bit OSes. If you have the RAM (greater than 4 GB) Photoshop will use that RAM as a scratch disk.Has CS3 improved on this usage? (As an aside, Microsoft has once stated that Vista will spur the move to towards 64 bit computing but their latest efforts have not shown any promotion of their 64 bit OS. I wonder if OS X Leopard will be the bellweather for 64 bit computing)[What Photoshop CS2 and Photoshop CS3 will do is if it sees your machine has more than 4GB of RAM in it is flip on the bit that allows reads/writes to the scratch disks to be cached by the OS. How well that works partially depends on how well the OS file caching works. – Scott]

  12. Albert says:

    Since I’ve a chance to “talk” to PS software architect, let me present my pet peeve :SMART MULTIPROCESSINGWhen Software are optimised for multiple cpu/core, they’re almost all trying to cut one task in pieces. They yield typically à 50% speed gain, because there’s ovehead, and the task si not totally splitable.That’s great when you deal with one task on one file.But that aproach is bad when you have multiple files to process.A Good (bad) example of that is Ligthroom doing JPEG export in batch.Each export to jpeg is optimised for multi-cpu (as both cpu seesm busy), of course it’s not twice as fast as if there’s only one cpu.Once again this is good when you have one file to export.BUT when doing JPEG export, you usually export a lot of file, let’s say 20.What Lightroom does, is to use two cpu to process each file one by one (with a 1.5 speed gain or less)A much fatser way to deal with the problem, would be to tell a cpu to process 10 files, and to tell to the other to process the other 10 files.There we would have a speed gain of 2.So smart multiprocessing would be that the software detect wether it has to batch process a huge number of frames of files, or if it has only one frame to process, and choose is strategy depending of the case.So a software should be able to choose intra-file multi-cpu optimisation when ther’s one file, or inter-file multi processing when there’s several.But developers, since they already suffered the pain to do the intra-file multi-cpu optimisation, just launch it regarless the number of file. It’s a waste.The software could be even smarter, gaucign the impact of the I/O speed and choosing it’s policy taking it in account.Ex : If you hav slow I/O, then intra-multi processing would be faster than inter file multiprocessing.As a side note, simultaneous file copies are totally ineficient (when from/to same volumes), because copying one file after the other is MUCH faster that copying the 2 files simultaneously which forces Hard Drive heafd to change position constantly.What do you think ?Could you pass that to LightRoom, or PS in batch mode.[Raising the thread split to the document or file processing level can work in limited circumstances. However, even if we could accomplish that, the basic hardware issue remains – even if an application was perfectly split, it still wouldn’t scale very well because today’s systems barely have one core’s worth of memory bandwidth. – Scott]

  13. Good discussion, sensible thoughts. It’s good to see that Photoshop CS3 is on the way … I’m liking the improvements I see in the beta. 64bit will be great when everything is lined up and ready. One step at a time.

  14. Lawrence Hudetz says:

    My thoughts have to do with running a 32 bit app on a 64 bit system.I gather from reading various articles that a definite increase in processing speeds of renderings is accomplished by running the 32 bit system on a well configured 64 bit system. Therefore, an immediate requirement for 64 bit PS is less important that accomodating that app on a 64 bit system. That is my reason to build a 64 bit computer; Allow the advantages of 64 bits to effect an increase in the capabilities of 32 bit apps. For me, with routine scanning of my considerable 120 images at 2400dpi or more, I would be quite happy with a 32 bit app that ran as if no HD scratch were involved! I can see that from my recent move to full digital acquisition. The Nikon files are considerably smaller than my scans, and running even the 64 bit single core processor on them is quick and efficient. I find at times that I wonder: “Is the rendering being done?” then I see that it’s all over!So at the moment, I have a single core 64 bit Athlon on a board capable of running the dual core. Only 1G of ram, which was deliberate, as paying another almost $200 for an effective increase of 30% or so in actual ram availability for my use seems to be poor use of my money (2G ram requires me to set ram use at 55%, whereas I am running about 75% ram with the 1G setup. My increase would be to 1.1G from 750M.).So far as ram speed, I am doing some validation work for a large silicon products manufacturer and some DDR3’s have been showing up. Even the sample versions are dynamite.I guess my view is that the 32 bit apps be able to run seamlessly on a 64 bit system, and that that system have the proper drivers. It would also be nice to be able to run 16 bit output instead of 8. Already, a Canon printer on the market can handle direct 16 bit output.[Without API support for 16bpc printing or display, we’re having a tough time with that one. – Scott]

  15. Albert says:

    Scott,I didn’t mean to raise the niumber of thread. I just said to use the same number of thread more effeciently.Rather than having 2 thread working on the same file will only a 50% gain.I said, just allocate one thread to one file, and the other to the other file. Each thread would work at 100%, for an averall 200%, while before we would get 150%So same amount of thread.Of course I’m aware about memory bandwith, but I think, Disk I/O would limit the effeciency first, but my approach, all thingw being equal is faster.[Memory bandwidth remains the central issue – even if two files were completely in memory and could be operated on completely separately on separate threads, the gain would continue to be small as each processor would contend for memory access. This is something that has changed dramatically over the last decade. – Scott]

  16. Brad Stiritz says:

    Scott,Thanks for the interesting discussion. As a professional PS user running on a fairly high-end system (2 x Opteron, 4GB ram), I strongly concur that there are higher priorities facing the PS team than a native 64-bit image.If you’re open to a little end-of-year griping, here’s my 0.02 view of something more important than 64-bit code: improved memory management. In my experience, this has long been and still remains kind of poor as of CS2. I mean, come on, why is it still necessary to close and reopen PS in order to get the app to release allocated memory (even after purge)? Using Windows TaskMgr, one can see literally gigabytes of ram consumed by PS, even after all images have been closed! Seems like PS isn’t playing very nice here. It can be frustrating… :-(Sorry to have to complain, especially on Xmas Eve, geez! but I hope you can sympathize…thanks for hearing me out,sincerely,brad[Brad, there is no need to quit PS, the memory isn’t being leaked. Holding on to the tile memory solves a number of computer-science-y issues, the key one being address space fragmentation – if we didn’t hold on to the memory, during the day we would be able to hold less and less of the image in memory and things would get slower and slower. Also, there’s a distinct difference between the Mem Usage column in Task manager and VM Size – one is working set, the other is address space usage. Putting an application in the background will allow the operating system to trim the working set usage, which more directly corresponds to RAM (yes, applications only control their address space, the operating system controls how that maps to RAM or disk). Those claiming that you need to keep as much RAM free as possible – well, that’s just FUD. We do experiment with different things, and the performance loss that comes with “freeing RAM” (deallocating address space, and the resulting fragmentation) is always enough that we’d put up with the occasional “why doesn’t Photoshop free RAM?” question rather than slowing down everybody’s performance. 🙂 – Scott]

  17. onno de jong says:

    Working on a Quad G5, I see that Apple’s apps can consistently utilize all 4 processors to a considerable extent, and Photoshop, which I live in for most of the day, rarely ever tops one processor, so multi processor/core utilization is poor. It is my hope that with Apple moving to Intel, Adobe will clean up its code. I realize that Adobe needs a separate rendering engine for cross compatibility purposes, and I am guessing that is the bottleneck. I expect Photoshop to be responsive with 4 processors available to me, and its not nearly what it should be. And Illustrator, we won’t even go there. You know the reasons behind it, I just experience it as a user, and I expect more.[Different applications hit different limitations in the system, and for different reasons. Photoshop used to be CPU-bound in a lot more cases a decade ago. But memory bandwidth has not increased at the rate CPU power has – to the point where only very heavy CPU things like video encoding can actually use all the processors available. Yes, I think it sucks, too. Ironically, it’s also possible that because our processing code is tuned and clean and CPU efficient (and thus much more likely to be memory bandwidth bound) that you are seeing this. Wish we could do something about it (besides becoming more wasteful of CPU). – Scott]

  18. Bernard Languillier says:

    Dear Mr. Byer,Thank you for this article. I appreciate Adobe communicating on this key topic.As a photographer using CS2 with large stitched and 4×5 scan images, I am really disapointed by the lack of 64 bits support in CS3.Frankly speaking, I am not totally convinced by the technical reasons you evoke for postponing this switch.I am aware that 64 bits application are not in themselves faster, and use up more RAM, but the lack of swapping is a key advantage when dealing with large data.I hope that Vista and 10.5 will be better at using available OS RAM as swap space, but in the absence of credible data, your bet is as good as mine regarding how efficient that is going to be compared to actual 64 adressing. It is a bet I would have preferred not to have to make.Regarding the current OS limitations, my understanding is that Apple is targetting OS 10.5 in Spring 07, while PS CS3 is targetted just a bit earlier.Had both 32 bits and 64 bits version been available on the same media, nothing would have prevented Apple users to start using CS3-32 on 10.4.8 before migrating to CS3-64 when 10.5 would have been released. You could even have made this switch automatical actually.Did the current Mac OS “issue” really play much of a role in this decision?To me, the decision to postpone 64 bit support looks like a decision that is more financial than technical.Obviously, only Adobe can decide Adobe’s investement policy, but in the end, it is a decision to limit cost on your side, that will mean more cost on your customer’s side.Regards,Bernard[I’m not convinced there is any cost on the customer’s side. You can already run Photoshop on a 64-bit system with 6GB of RAM and see the speed improvement the system file cache makes when there is memory for it. And we ran significant processing tests hoping to see speed improvements that would justify the costs – and we really aren’t talking financial costs, but the other features we wouldn’t have been able to do. – Scott]

  19. Rob Cain says:

    Not that I blame Adobe for any of the problems with the advance in technology, but once again, capitalism kills the progress of technology.Yes, A very small number of users actually use XP64. I tried it and I couldn’t get over how quickly everything broke, thanks to the almost total lack of any kind of support from the large majority of vendors.It’s a nasty circle — people won’t buy XP64 because the software and hardware doesn’t support it fully. The software and hardware don’t support it fully because the developers know that a precious few people use XP64 and they’d take a financial risk in developing for it. It costs everyone money to make technology really progress. So the loop goes on and on and slowly causes 64-bit technology to die out. Eventually some guru will come up with a compromise that lets you utilize 64-bit features without having to use a fully 64-bit operating system and… oh wait.If that don’t sound familiar~!I think Adobe would do well not to ignore the possibilities of an early start. Sure you might lose a little dough in the short run from limited audience. But Adobe’s product line going 64-bit would give 64-bit OS versions a real positive boost, and having the first foot in the door would toast competitors who will be coming into the party late. Corel? Pffft.64-bit technology isn’t about improving what we do now, not really. The average user has 1-2 gb of ram, hardly enough to warrant avoiding a memory allocation problem. Moving to 64-bit is about removing the roadblocks before we even get to them, letting us stretch our abilities and do more, maybe not now, but definitely when the time comes. Sticking with 32-bit will result in a mad scramble to switch if (not when) the 64-bit market finally makes it through its dying chrysalis.[Interesting. I still think it’s a when not an if, for what it’s worth. – Scott]

  20. George Middleton says:

    Scott, thanks for your availability and all your incredibly helpful answers and information.“..having the operating system use any unused RAM to cache scratch disk reads and writes can be nearly as effective (depending on how good the operating system is at this – and there are even a few add-on products which can make it even better) as having Photoshop itself being able to hold all of scratch within it’s own address space. “By add-on products, do you mean ram disk and/or caching software? Are you referring to hardware products as well- such as using flash drives and hybrid drives? Would these be beneficial to Mac as well as Windows?[Yes, I meant caching software. I haven’t watched enough on the Macintosh side to know if there’s a potential benefit there as well, but there could be. As for flash drives and hybrid drives, we just haven’t seen or used these yet, so we don’t have any idea what sort of impact there will be. – Scott]

  21. Scott, there is one thing I wonder. If OSX is to become fully 64-bit and Windows Vista already is, can we assume that these two OSes will become mainstream somewhere in 2007? If so, when do you think majority of PS users will start equiping theirs computers with more than 4GB RAM? Given memory prices compared to the price of the rest of the system (or single PS license) it can well happen in 2007, maybe 2008. I bet you want to be prepared for this moment.[So, Photoshop will still benefit from having more than 4GB of RAM in a system – 6GB seems to be a pretty good sweet spot right now for the current 32-bit OSes. With Leopard or Vista 64-bit installed the sweet spot might be higher – without needing Photoshop itself to be 64-bit. I think the key on the Windows side is watching when OEMs pre-install the 64-bit version by default – still an issue right now because of drivers. We’ll be watching the switchover rates very carefully. – Scott]

  22. Janek Kozicki says:

    Concerning 64bit operating systems: As you said – Mac isn’t there yet. Windows has problems and considering their history how long it takes to make anything we can’t expect it too. So how about linux?A good read about “switch to 64bit”:http://www.catb.org/~esr/writings/world-domination/world-domination-201.html[Thanks for the extremely interesting link. Linux has always had a place in the back of my mind, and I do try and keep an eye on how things are developing in that world. – Scott]

  23. Jeff Bernstein says:

    Scott,Again, thanks for posting and sharing your insights. I love it. As a system integrator, we have seen very little in the way of speed improvements. We were hoping to see more speed by upgrading our clients from Dual G5s w/DDR RAM to Quad G5s w/DDR2 RAM. Our clients and ourselves were underwhelmed.Moreover, we have seen in multiple instances where by adding more than 3GBs RAM, things tended to be a little slower. Turning on and off layers, seems slow or delayed. We have tried playing with and without “Bigger Tiles”.Is there a magic combination of the optional extensions that needs to be enabled/disabled for optimal speed and response? Are there certain preferences we should tweak (we turn down the histories, for instance)?Keep in mind that many of our clients have file sizes that ~1GB.Thanks for your help and keep up the good work.Jeff[I don’t think there’s ever going to be one combination of things that’s going to work best for all of your clients. In general, I would think that using Bigger Tiles will help with dealing with those larger files, but it will take away from interactivity a bit. I would also think you would see a big win by bumping the amount of RAM up to 6GB, but I’m not sure how well what we see in the lab will be reflected in real-world situations. Also, when pushing systems that hard, it will be important to watch the amount of free RAM using Activity Monitor, to make sure that the memory usage slider isn’t set too high. I’m going to push for getting a tech doc together with some more detailed information. – Scott]

  24. Cause and Effect says:

    Sorry, I had to post a comment. Before I write anything, I have to commend you Scott for writing responses to each reply, quite amazing. I got here from AppleInsiders mention of this, so I’m sure a lot more people than usual will be posting comments. Maybe I can stave some of them off. While a couple other people mentioned Leopard, I have to mention it too. I’m just astonished that you didn’t mention Leopard in a post about a 64-bit Photoshop. Leopard will be the first 64-bit OS that will run Photoshop, as well as the other 32-bit apps, drivers, etc. Not some joke, separate product like Window’s 64-bit sideshows, but the real deal. A huge amount of the design industry use Macs, and the vast majority of pro photographers use Macs. And all pro photographers use Photoshop.Adobe is likely making more money from Windows idiots who got their first DSLR, but the pro’s with digital backs are using Macs. Those same users dream of being one of those pro photographers at night. People buy Photoshop on prestige and reputation. The competitors to Photoshop charge far less, but people who don’t know what they are doing spend a lot on it because they know the pros use it. They have no idea what a colorspace conversion is, but they spend $650 none-the-less.Adobe is the 800-pound gorilla of the DTP industry now, a genuine monopoly with the hostile take-over of Macromedia. I’ve been using Photoshop since version 2.5, since 1994, ironically at the PPC transition. I would have no issue switching to a competing product, though. I expect Adobe to push Photoshop to be the best damn photo editing package out there, but more than that, I expect Adobe to make Photoshop the best damn photo editing app they can. So, it’s odd to read an article talking about CS3’s lack of 64-bit support, citing lack of an OS, with the OS arriving the same time as CS3. You know as well as I do that when Leopard hits, every pro Mac users will be moving to it. People are waiting for Leopard to get their Intel machines. People are also waiting for CS3 to buy their Intel machines.As you know, moving an OS from PPC to X86 is no small feat, and it’s remarkable Apple pulled it off so well, even though that’s what people expect…them to just do everything so damn well. It’s likely because I am so spoiled with an OS vendor that works it’s ass off so I don’t have issues, to give me the best, that I expect more from Adobe. If pro photographers switched from Photoshop to another product, so too would the wannabes. That would happen very quickly. So, it’s in Adobe’s interest, in regards to Photoshop at least, to make it the best they can. Apple’s Aperture is addressing the needs of high-volume photo work-flows, and that is just the user a 64-bit Photoshop would aid. Apple can add Photoshop style raster editing at any time, Apple can also release their OS and software to the rest of the X86 market at any time.Because a 64-bit version of Photoshop is not practical in today’s market is a very silly reason not to be working on it now, as it will be practical in a few short months. The first genuine 64-bit OS platform for Photoshop is shipping the same time as CS3. And what about Lightroom? I guarantee you Apple is already working hard to move their pro apps to 64-bit, and a simultaneous release would not be surprising. All their pro apps, Final Cut, Logic, Motion, Shake and Aperture will benefit from a loaded MacPro running in 64-bit, and so would Photoshop.You mention that “things would get interesting” with a 1GB file, which is interesting to me, because I work with files are over 1GB. Start with a 100MB image, add some layers, and it’s not long before it’s a gig. Try a file from a pro digital back, where you’re starting out with an image already several hundred megabytes large. Yeah, things get interesting real fast. With CS2, Adobe allowed people to quickly make larger files, by introducing 32-bits-per-channel color, yet another reason serious memory would help. Will Joe-Windows-User benefit from a 64-bit version of Photoshop? No. But I sure as [edit] hope Adobe is not targeting Photoshop at him now. That’s what Elements is for. I know that there is a delicate balance, giving Elements enough features so a dumbass feels like they have Photoshop without cutting into the dumbass who would otherwise have spent more for Photoshop. Oh! I have an idea! Make Elements run only in 32-bit, and Photoshop run in 64-bit! Oh my gosh! He’s a genius!But seriously. The multiple SKU line is bogus. How many desktop retail versions of Leopard will there be? One. Is there some evil monster that prevents Adobe from putting a 64-bit version and 32-bit version of an app on the same DVD? You could release a universal binary, 64/32-bit. That’s what Leopard is, and so too will be the new apps from 3rd parties. Those same 3rd parties who got versions of their apps out for Intel in a hurry. Or were you talking about Windows? How about when Microsoft announces their standard OS will be 64-bit, then worry about a 64-bit release for them. I think most Windows Photoshop users are using it for web design, and so would gain no benefit from that anyway.Apple has what, a 4% market share? Something miniscule like that. Yet a huge, if not majority of DTP work is done on Macs, the vast majority of pro photographers use Macs, they have at least 50% of the music industry, Final Cut stole the video market long ago, etc. So, considering that the other 96% of computer users run Windows (there is a sliver running Linux), it’s pretty obvious that the vast majority of Mac users are not doing ordinary things with there machines. They are doing creative things with them, pushing the limits, just like the two Mac users who made Photoshop.Why would Adobe want to aspire to mediocrity? Actually, can I talk about Final Cut a minute? So, once upon a time, there was a guy who worked at Adobe. He developed a program called, “Premiere”. That product went on to become the standard for video editing. But, as its use grew, it’s users needed more and different features. They needed a better work flow as they were working with projects longer than a few minutes. So, this man told Adobe they needed to change the program to be in line with it’s customers. Adobe told him to go [edit] himself. He quit, got a job with Macromedia, developed a program called Final Cut, Apple bought Final Cut, and the rest is history.Do we see any parallels here? CPU’s have been 64-bit for some time now, a full 64-bit OS (that works fine with it’s 32-bit brother’s apps and drivers) will be out around the same time as CS3, and I haven’t heard of a single memory maker who said they were planning on making ram slower. Both Intel and AMD are releasing hardware with fatter busses this year. You have a lot of users dealing with 1GB files NOW. Dealing with them yesterday, last month, last year and before. A serious upgrade is to be had for them with a 64-bit system. You know that, you admit that. Photoshop was an elitist app back in the day, just like most Mac users are. Adobe’s days of pushing the creative market with stunning apps ended years ago. They give birth to new versions of the SAME apps, and the birthing process is usually long and with little gain. What has Adobe done new recently? Tried to make a copy of Aperture? I mean really.If Adobe’s current Photoshop team is too small to handle this, then why not hire some new people? Is Adobe hurting financially? Get a 64-bit team started. They can handle hashing it out, working with 3rd party developers, getting it primed. I mean, when Adobe releases a 64-bit version of Photoshop, are they going to drop the 32-bit version? Likely they would need 2 versions to support their market initially. So shouldn’t they already have a 64-bit team? From what I am reading, it seems to me like you are saying Adobe plans to release a 64-bit version after the majority of computer users can take advantage of it. What the [edit]? The majority of computer users do not use Photoshop!One of the brothers who created Photoshop moved on to ILM to work on cutting edge [edit], presumably because Adobe seems to have no interest in pushing anything (aside from marginal upgrades). The pro’s can benefit from a 64-bit version, and the technology is out now, with the OS shortly. Sorry for repeating myself. If I ran Adobe I would probably fire a lot of people, and replace them with those who shared the goals that made Adobe. Going out of their way to invent and produce the best stuff, not trying to maintain a market position and buying any serious competitor. I’d happily work hard on the Photoshop team to come up with some revolutionary, not incremental ideas. But I’m not boring enough for Adobe, politely put.Anyway, my filter-as-adjustment-layer idea is coming to market with CS3, and I am sure this has been one of the biggest features people have wanted for some time. It must have been a bitch to program. So, congrats on that. I haven’t tried the beta, I’ll wait for the final release, along with Leopard, and my next Mac. And I’ll wait for a 64-bit version of Photoshop, which should be out in about 3 years I guess. Then again, maybe a competitor will get something out sooner. I doubt it, but I’m open to the future. Apple could wipe out Photoshop on the Mac in a hurry, but I don’t want Apple spreading themselves too thin, I think the iPod is already overkill.I appreciate your honesty and please don’t take my ideas or opinions personally, as I am talking in broad strokes about Adobe, and I am sure you are an awesome person. Thanks for posting this info. If you haven’t lately, I’d recommend trying Photoshop 1.0.Yes, it runs on Macs today, nearly 2 decades later. It runs great, actually, and is very useful, doing a lot of what Photoshop does now. I’ll e-mail it to you if you don’t have it, it’s only 400K. If I had worked on that, I would be damn proud. Maybe that could inspire some of the Photoshop team to want to make the next Photoshop so good it could stand up 20 years from now. That’s a tall order, for sure, but we should all push for the best. I am looking forward to CS3. To complement the current team, CS2 was much better written than CS1. I understand the teams are different, and a lot of the people who did CS2 are working on CS3, so I trust it will be a decent version too. Let’s all close our eyes, forget CS1 and hope for the best with CS3 and beyond. I’ll call it Photoshop 10 and celebrate it’s release, 64-bit or not.[Note, I clipped out some language in the comment. I appreciate the time that went into such a long comment. There are things about Leopard and what will be available for a 64-bit app that mean it’s no small issue – far, far more work than could ever be done to an app already in beta. And that’s assuming that the OS was already released and stable – working on a pre-release OS can be an immense nightmare, and can take a bunch more work. And it isn’t a matter of simply adding more engineers – they aren’t interchangeable, you know. Nine pregnant women and 1 month do not a baby make. This is complex stuff, and a ton of resources were already consumed by the Macintosh Intel transition. – Scott]

  25. Van Daniel says:

    Scott, you are amazing to offer this level of communication with your customers, so please, don’t be offended, but I just don’t understand your replies to those who want to talk about 10.5 Leopard.”Yup, looking forward to it. – Scott”It’s only a few months away… very close. So why not develop for it? You have beat around the bush, and not offered an answer to that. Almost all new Apple hardware (except one model: the low end Mac Mini) has 64-bit processors with multiple cores. A lot of professionals have bought, or will be buying, this latest hardware. We are also very likely to pounce (har har) onto Leopard fast. Apple’s own data on Tiger adoption show that it was accepted widely and quickly by the user base. So, my question is, why aren’t you committed to being there for us with the 64-bit app you claim to be “looking forward to.” Leopard addresses so many of your points in the post, but yet you make no mention of it. And then when the comments mentioned 10.5, you just smiled and nodded and gave no explanation as to why you are not developing for it. You have had 10.5 since August, have you just kept your Apple Developers box turned off? Or what, Microsoft wouldn’t allow you to release a 64-bit Macintosh version while they are stuck with 32-bit for the foreseeable future? I offer this theory because, your ignorance of Leopard, both in your post and in your development, feels more political than computational. If you can do it, like you said you could when OSes allow you to, why not give us something with Leopard? To ignore this (and us) seems deliberate, and that is frightening.[Even if we got a full drop of Leopard, which was complete, and had good, complete documentation on, the reality is that for a large application, there’s not much you can do at that point in the schedule but fix bugs and be compatible. But go visit Apple’s Developer page for Leopard. What API is missing from the 64-bit side of things? Quickdraw. You don’t go ripping out the use of something as ingrained as Quickdraw and replacing it in a mere matter of a few months. So, no, not ignoring Leopard. But going to 64-bit on Leopard is far from just flipping a switch. – Scott]

  26. [Ah, yes, single routines where the 32-bit version of the routine suffered from lack of registers is indeed the birght spot of 64-bit conversion. Note that we did such tests with Photoshop’s versions of such routines, and probably because the Photoshop 32-bit versions have long been optimized to work around the lack of registers and slow 64-bit math, there were no such big wins. – Scott]Yup the reason Gaussian Blur shows such a big win in Paint.NET is due to its use of 64-bit math. Photoshop seems to have some secret sauce that enables its implementation to be much faster regardless, so props on that.One thing I don’t see discussed yet is that a 64-bit version of Photoshop couldn’t (or shouldn’t) be done as “just a recompile.” The reason I say this is plugin compatibility: every plugin out there right now is sitting in a 32-bit DLL. On Windows, a 64-bit process cannot load a 32-bit DLL (WOW is there as a subsystem for enabling 32-bit processes to work with the 64-bit kernel). So, if you wish to maintain compatibility with all the existing plugins I immediately see two ways to go about it. One is to go the IE6/7 route and have both 32-bit and 64-bit versions of the application and dll’s. Users would then be burdened with figuring out which one they needed to use for the current task at hand.Another possible implementation would be to run 32-bit plugins out-of-process (I’m specifically thinking of filters here), and to use some tricky messaging and shared memory mechanisms to ensure that the user still perceived the two processes as one application. Having glanced through the SDK awhile ago, I’m guessing there’s enough leeway in the host implementation to allow this. The problem is that of cost: implementing an inter-process UI in a cross-platform manner doesn’t sound like something to undertake without some large cajones, not to mention a healthy testing budget. Then again, this might be worth implementing in the 32-bit version as well for consistency (more shared code = less special-case debugging) and even security or stability (plugins would not be able to easily muck with Photoshop’s internals). Heck, why not run all plugins out-of-process? (Mind you I’m saying this out of optimism, not as a challenge or critique.) Also, with this implementation, plugin authors could choose whether or not to publish a 64-bit version based on their own performance and costs.Hopefully this second method is feasible both technically and financially for Photoshop. I think it would simplify things quite a bit for users and help encourage 64-bit migration. Or rather, it would avoid discouraging it due to technical mumbo jumbo blockades: “What’s a 64-bit?”-Rick Brewster (Paint.NET lead dev)[Rick makes an excellent point about plug-ins. We try very hard to remain plug-in compatible across a number of versions (the amount of work that went into keeping CFM plug-ins loading in Photoshop CS2 on the Macintosh, for example, was huge), and doing out-of-process will be one choice we need to make when we move to 64-bit. One of the complications there is the number of frameworks that have been provided to plug-ins over the years – the broader the number of APIs provided, the more difficult out-of-process becomes. Performance issues and debugging can be very difficult with out-of-process as well, especially with broad APIs. – Scott]

  27. Igor says:

    I would like to add my 0.02 cents here.I had a chance to use Photoshop CS2 and I always disliked the idea of independent VMM.I understand that in the days of Windows 95 you needed alternate solution due to the fact that Photoshop wasn’t native Windows application, but that was years ago and I really can’t believe that today’s VMM in say Windows XP is not good enough for simple image processing application when it works just fine for any other purpose (in my case 3D reconstruction of x-ray CAT scans).I am also a developer and I am working a lot on code optimization (assembler, SIMD, C/C++), so it is also hard to buy the story about bandwidth limitation. Surely you must be doing something wrong there, because my co-worker and I have managed to utilize all four cores in Intel Core Quad QX6700 CPU for said reconstruction without hitting the bandwidth limit of DDR2-800MHz memory. In my experience key is to optimize memory access pattern properly and to avoid aliasing which leads to cache trashing.I understand that Photoshop probably does a lot of things which are not compute bound and I wonder if SIMD could be of any help in the unlikely case that it is not already used?And finally, I would like to ask if 16-bit depth will ever work without that anti-overflow hack?By “anti-overflow hack” I mean shifting values right one bit when importing raw 16-bit data and one bit left when exporting it which results in all odd numbers in a dataset becoming even and leading to loss of precision. Surely we have power to work with full 16-bit numbers by now, and that is exactly where you could put more computing pressure to aleviate bandwidth problems.I also humbly offer my and my co-worker’s services to Adobe when it comes to code optimization for current x86/x64 hardware platforms and image processing algorithms. Let me know if you are interested so I can give you our contact details and more info about our expertise.Here is an example of my optimization skills at work:http://www.intel.com/cd/ids/developer/asmo-na/eng/dc/code/languages/194751.htm[No, the operating system VMs aren’t good enough to get peak performance while maintaining interactivity. The page sizes are very small, and don’t have the 2D locality needed for responsive image editing. The memory hinting interfaces have too much overhead to replace what we’re doing now. I’d love to not have to maintain our own VM system, but I doubt our customers would want to put up with the loss of performance – and we check the performance loss with every new OS, hoping. As for the bandwidth issue, the problem is very, very real. We do cache management, prefetching, use SIMD, and all the other tricks we can to maximize the use of that bandwidth, but most operations are now bandwidth bound. The simple truth is that there isn’t enough bandwidth for the number of cores in current machines for all but the most compute bound operations. You’re lucky to have a very compute bound operation, I’m envious. I remember when we were able to scale most operations to more than 6x on an 8 way machine, and I keep hoping that an interconnect breakthrough will come along to undo the logjam. As for 16-bit, it’s not about overflow, it’s about having a center value to avoid operation bias. That’s worth so much performance in critical parts of the application it can’t be ignored. -Scott]

  28. Janek Kozicki says:

    HelloIn my previous comment (still hasn’t appeared 😉 I pointed that in order to make a succesfull switch to 64bit the most desirable approach would be to switch to linux. That article titled “world domination 201” (URL reminder):http://www.catb.org/~esr/writings/world-domination/world-domination-201.htmlmentions that one of crucial points to help with the switch could be a so called “killer app”. In this case it could be YOUR photoshop software. To prove my point, check the results of Novell survey about “most wanted windows software to be ported to linux”:http://www.novell.com/coolsolutions/feature/16917.htmlVery big surprise (also to Novell, who performed the survey) was that photoshop occupies the first place! While AutoCAD is second. Many people would expect AutoCAD to be the first.You, people at adobe, can decide about linux’s future for the next 50 years 🙂 (because it’ll be 50 years before another switch, to 128bit hardware). Just take time to read that “world domination 201”, in earlier link, to understand my point.Maybe you will decide to port photoshop to linux, then? :)best regards, Janek Kozicki[Thanks, and I do hear you. – Scott]

  29. Dear Scott,Thanks very much for this excellent discussion. I am pretty much in the same boat as Bernard, above, and have needed for a long time to impress on the Photoshop team how terribly damaging to my experience of Photoshop the current RAM limits are.To appreciate how bad things get, you need to create an imaging situation where your scratch requirements reach something roughly on the order of 9 Gigs, and then try to perform a few dozen operations to that file. Contrary to your guess above about things getting problematic when the file size reaches 1 GB, I routinely have serious problems with files that start off (at least) at between a quarter and one half that size. The RAM requirement grows for many reasons, and the number of those reasons also continues to grow. And I am one of a great many photographers in this same boat (although unquestionably a minority for the moment).For example, if one stitches a dozen frames of 48-bit data from a mere Canon 5D (just 12.7 MP) together and preserves the layers for retouching, the resulting .psd is nearly 2 GB. Needless to say, you can’t even *open* the file without getting into scratch disk use. Or if one takes a smallish scan of a sheet of 4×5 film (230 MB) and replaces it with a 48-bit version, you’re already into serious pain at 460 MB, what with History states not being kept at 1 (because History is valuable for speed too) or multiple versions of the image (2 or 3 image layers where each layer must be kept and was very hard to make), or pasting two of these images side by side for printing on 44″ roll paper, or any of many other reasons.My scratch requirements in recent years have very often exceeded 5 GB and in some instances have exceeded 9, and in the future could easily exceed something like 20 GB if I’d dare to even try such masochistic things. When the scratch requirement is even 5 or 6 Gigs, the time required to do every little step is several minutes. It’s just awful. It reminds me of 1996 all over again — even though the machines are 1,000 to 10,000 times faster.The rest of the time, speed in PS is fine — varying from what seems to be very good to curiously sluggish. But when the scratch requirements exceed the available RAM by more than just a little bit, the process begins to fall flat on its face. And I strongly suspect that the team has just never experienced how awful it is to be waiting for 7 Gigs of hard drive writing and/or reading just to do one little step, over and over and over and over, in order to get to point B. Otherwise the switch would have been on the schedule for CS3. It’s almost the only thing I want from PS. That and a good selective color correction tool with 3D selection and 3D movement, which strikes me as being about ten years overdue.If OS X can take up the slack, without PS going 64-bit, that would be fine, but the current limits on usable RAM are just way too low, even after being doubled, for lots of high quality work. I don’t know if you heard about the new pixel-gobbling monsters from Seitz in Switzerland. They are about to start selling a 360 panning camera that grabs 7500 pixels vertically by many, many times that number horizontally in a single, quick scan. With an 80mm lens that works out to about 470 million pixels at 48 bits after RAW processing. And the camera can do a back shift, so that you can make two scans, and stitch them together, thus extending the height to 13,500 pixels. And then there is the GigaPixel project and efforts like it that stitch hundreds of Canon frames together. Apart from the one-time jump to digital capture and its reduction in pixels needed for equal detail, the trend is definitely toward bigger files. Much bigger. Tom Knoll and Dave Story stopped by the Seitz booth to talk about these bigger files with Seitz and my friend Henry Wilhelm, here: http://www.roundshot.ch/xml_1/internet/de/application/f755.cfmWe really need to see this dealt with right away. Imaging is getting closer to being able to replicate the actual experience of seeing. That takes a lot more pixels than most people are used to thinking about.I hope you all enjoy the engineering rat race. It must be quite fascinating, but also hard! And Happy New Year to all.Joseph Holmes[Oh, terribly hard, and Happy New Year back! No matter how much I wanted to do a 64-bit version this time around, it just could not have happened. If you don’t already have a RAID box set up for scratch, look into it. We’ll also try and get together a tech doc for improving large file workflows. – Scott]

  30. Miklós Fazekas says:

    I’d assume that on the Mac side the porting to 64-bit Carbon api is also a serious issue. Deprecated APIs like QuickDraw, ControlManager, QuickTime are not available in 64-bit Carbon.[Yes, a very serious issue. Already been working on it, but things like that take large amounts of work and time. – Scott]

  31. Igor says:

    Nice to know that not all comments get published.[Patience! Can’t a guy watch a little New Year’s football? 🙂 I really do read and think about the responses, so it does take a bit of time to get through them. – Scott]

  32. Jeff Rowe says:

    Thank you for your insight. I use a workstation (5G dimm, 2 3.8 Xeons, 15k raid) CS2 (great product)with Win 64. Great machine but its all dressed up with nowhere to go. I have struggled with driver issues for over a year, I had hoped that 64-bit computing would have arrived by now! I’m on the verge of wiping the machine and installing Win XP 32 after recently receiving an X-RitePulse spectrophot.,because there are no 64 drivers. It does not look like things are going to get better soon with either flavor of Vista. Without drivers, great hardware is of little use. Happy New Year![Exactly. But I expect with Vista the advantages of running the 64-bit version of the operating system (even with 32-bit applications) are enough that I suspect as we crawl up the adoption curve, pressure will quickly mount on the infrastructure items that need 64-bit drivers to even work. – Scott]

  33. Igor says:

    “Patience! Can’t a guy watch a little New Year’s football? :-)”I appologize for being impatient and I wish you Happy New Year.”The page sizes are very small, and don’t have the 2D locality needed for responsive image editing.”Isn’t 64-bit OS capable of larger page size via MEM_LARGE_PAGES flag in VirtualAlloc() API? That alone could make it worth transitioning.You are right about our operation being compute bound but when we first run the threaded version on a quad core CPU it was bandwidth bound and it took 34 seconds just like it did on dual core CPU since two cores were not doing anything usefull due to bandwidth limit. We had to tweak memory access pattern and now it takes only 20 seconds on all four cores so yes, we are again compute bound.[With large page support, the devil is in the details! First, the flag is only available on Vista, and second, the restrictions on it make it very dangerous indeed – the memory is not pageable, so it’s going to take a lot of careful testing to see if using it is even reasonable, and we wouldn’t be able to be nearly as aggressive about how much memory we could allocate that way. Your point about tweaking routines as it’s noticed they become bandwidth bound is well taken; it’s one of the things we’ve done over the years, so unfortunately there isn’t much, if any, bandwidth usage that can be squeezed out of most of them anymore – it’s pretty much been done. – Scott]

  34. Andrew says:

    Port applications under a 64-bit platform can be much more complex, than can seem. Especially it concerns to large complex systems which is Photoshop. In Photoshop great volume of an old code, a code of old libraries is possibly used. I was engaged port one such system under 64-bit Windows system, and I can tell, that this unpleasant employment. The most important, we could not find at that time the suitable utility for the analysis of the code, revealing incorrect places. We have tried two lint-like systems and have remained are dissatisfied.I did not enter the given interesting discussion as I had nothing to add. But here it is literally one of these days, I have learned, that there was a first version of system which I so long waited. Viva64 – the static C++ code analyzer. It is specially developed for rendering assistance to the developer at port applications. I have decided to share with you this information as probably it will save to you many millions neurons at port of your appendices on 64-bit systems.See: http://www.viva64.com

  35. Andy says:

    I have been using xp x64 now with photoshop for about a year, granted drivers are not simple, however the extra memory support is a godsend, im currently running dual quad core xeon system with 16GB ram, i use dxo alot which multi treads very well using all 8 cores sitting at about 14g ram, under I386 this wouldnt happen. i find it very very easy to get photoshop paging, 2,9gb ram is nothing. when im working with my 39Mpixel files, open up a few and it grinds, even though i have a 15k raid 10 system. Now is the time that adobe should take the bull by the horns with vista coming out[What you’ll find with Vista x64 is that all of that memory will, in fact, get used for caching Photoshop’s reads/writes to scratch. It’s not yet clear if being a native x64 application would even be a speed improvement at that point. – Scott]

  36. SonnyShogun says:

    Recommendation for new Wintel pcI have read your blog and Q&A with great interest. I am in the position of buying a new Wintel pc with Vista (32 bits). What would your recommended spesifications be for the relevant hardware to get a high performance PS-system? How should the system be set up?Thanks in advance![It partly depends on what else you will be doing with the system. For Photoshop specifically, it depends on what kind of images you will be dealing with. If very large images or images with many (>100) layers, 4GB or event 6GB is desired. At least two cores, but the returns diminish pretty quickly beyond that. RAID arrays can help. A search for “Photoshop Acceleration Basics” will yield some useful information. – Scott]

  37. Dan says:

    I’ve been using Photoshop since they fixed the memory problem in v2.51/Mac; and switched over from Mac to NT4 at PS5. MacUser Magazine all the way back in 1994 did a Photoshop shoot-out, stressing the free memory size needed to be at least 3x the image size; and ever since then every high end Photoshop workstation I’ve configured since then has been both stuffed with RAM and had a RAID 0 scratch disk [though one monster back in 1998 had sixteen 10k drives in a 2 channel U320 hardware RAID *4* array, for incredible file open & save speeds.]Anyway, I just left a customer that has a brand new dual Xeon PC he built on a SuperMicro mlb with 4 gB of RAM & 64 bit NT6, a/k/a/ “Vista;” and, as the owner of a drum scanner, he too generates files that get into the gigabyte range when layers get added.When I read the entire column, including your replies to comments, I found the PSD groups’ reasons for not building a Win64 version almost exactly the opposite of Microsoft releasing Exchange 2007 *only* in a 64 bit version (for production servers). Please see “Exchange Queue&A” in TechNet Magazine at:http://www.microsoft.com/technet/technetmag/issues/2007/01/ExchangeQA/default.aspxfor their reasons in going the opposite direction.

  38. Dan says:

    `Ya know, after chewing on what you wrote, I recall similar development cost arguments being made about (Mac) 32 bit “dirty” apps (breaking the 24 bit barrier); the 68040 cache compatibility, the Quarda AV (660AV & 840AV (which Photoshop tapped into the DSP) nicely) compatibility problems; the PowerPC compatibility issue with the “fat binary;” the “obese binary” for Rhapsody; and yada yada yada as new hardware is introduced…The Rhapsody & OSX issue was operating system related, while the others are hardware related. Of these, I would compare the 68k –> PowerMac transition as being the closest to the x86 32 & 64 bit position where we are today.In fact, with over a year since the 64 bit NT versions have been released with XP & Win2k3; and with the AMD64 adoption exceeding industry forecasts, I would make this bold statement:There are more 64 bit NT users than Mac users, since Mac is only 4% of the installed base.Dan Schwartz[Exchange and Photoshop are different in a number of key aspects that affect the timing of a 64-bit move. First, Photoshop is already able to deal with data sets much larger than 4GB by having it’s own VM system, so the 4GB address space limitation isn’t nearly as much of a barrier for us as it was for Exchange. Second, Exchange is a server product, and isn’t as dependent on an ecosystem of things being available (such as printer drivers, color calibration drivers) as Photoshop is. The number of Photoshop customers that could potentially move to a 64-bit system is currently still very small. Not to mention that to keep compatibility with 32-bit plug-ins will require a large piece of work. While similar to those other transitions, it’s more work for less benefit. There are problem sets for which the additional address space is actually necessary, but it’s a pretty small set. It will be interesting to see how things shape up over this next year. – Scott]

  39. psychicist says:

    The reasons the author mentions for not releasing a 64-bit build on Mac OS X (because it is mostly 32-bit) and Windows (because it lacks drivers) are not valid for other operating systems like GNU/Linux and Solaris.So why not port Photoshop to these fine operating systems that run just as well in 32-bit as 64-bit and are more stable and faster as well?The only reason a pure 64-bit GNU/Linux OS is worse than 32-bit is because of the lack of 64-bit versions of Adobe Flash and Reader, Windows codecs, VMware and a bunch of other proprietary software.All free and open source software is 64-bit. The advantage of pure 64-bit software is that the entire system is 64-bit clean without 32-bit compatibility libraries and executables. Possible performance advantages are a nice side-effect.Until Adobe, VMware and others get their act together I will have to run Adobe software in a (32-bit) chroot or virtual machine.[Photoshop was on Solaris and Irix at one point (2.5 and 3.0). Having done some of that work, I’m familiar with what it takes to move a large application to a new platform, and it isn’t easy. – Scott]

  40. Ms Training says:

    Phew I nearly bought a 64 bit computer[Note that there are still advantages to running a 64-bit operating system on 64-bit hardware even with 32-bit applications. – Scott]

  41. jimcollier says:

    Work on the 64-bit version…please! I work on lots of panoramas (pushing 100 megapixel and in 16-bit), scanned images of >1gb each, plus large numbers of other modestly large files (by today’s standards–10mp cameras and scanned 35mm)–each with up to a dozen or so intermediate layers. All in 16-bit mode.It’s the scripts and actions that are really killing me–even on the otherwise modestly sized images. These open up multiple, logically “nested” temporary documents, each having many layers. I have to organize everything in batches, so I can click “OK”, and walk away for a few hours while it …griiinds… away.(Whereas if the files are “small” enough, it happens completely in-memory with no paging and is lightning fast. That’s how fast I need it all to be, otherwise it’s a monumental productivity killer. Time is money.)I’m fully aware that I’d receive benefits with a 64-bit OS and >4gb of RAM even with 32-bit Photoshop–by allowing Photoshop to have 3gb itself, plus more ram for plugins, plus additional ram over that, as much is available, for OS caching of the scratch disks. But I really need a compelling reason to spring for 16gb of RAM rather than a mere 8 (to save another hassle of an upgrade step later), and I really need to save as much time as electronically possible. 64-bit Photoshop–or a suitable 64-bit, scriptable competitor–would do that.Reading between the lines (well really just by using the application for many years), I interpret the problem as this: If you guys weren’t carrying so much legacy baggage with Photoshop and had wiped the slate clean sometime in the last several years with modern design practices and patterns–and a framework like Qt (as with Album), you could be ready for 64-bit in a jiffy. (Not to mention you could have also ditched the horribly inconsistent interface elements that variously span at least a decade in UI conventions!) Think how liberating that would be. I can’t even imagine the horror brainstorming sessions you guys must go through to get new features to “fit” in with the tangled web of various “standards” of the existing stuff.We, your power users (and powerless users), are suffering for said baggage. I usually agree that “all new code” is a phrase that means “we took everything that was tested rock-solid for years and broke it”. But in some cases–and at some regular interval such as a decade–it’s just essential to keep innovation moving forward freely. When Steinberg re-wrote the spaghetti code of Cubase from scratch, it removed the binders and the shackles they were weighed down with, and they exploded with new innovations from there. Besides, I’m getting pretty sick of paying for expensive upgrades seemingly every year with minimal new functionality per dollar. I could use a good break while you guys rewrite the application from the ground up.So when the board gets ready to replace Chizen, give me a call. I’ll get Photoshop on the right track. Plus I have a killer new app idea to get out to the market: “Adobe Eyeballs”. When you move your cursor around, little eyeballs in the bottom corner of your screen track it![I hear you. No worries, it won’t require a re-write. Note that some of our tests show a benefit of going from 8GB to 16GB RAM on Mac 10.4 and Vista x64 (you have to install the Force VM Buffering plug-in on the Mac). I’ll have to write up something on the big-memory things we’ve figured out. – Scott]

  42. Michaelography says:

    Hi Scott,Thanks for sharing. I hope this isn’t too off topic. Does PS3 take advantage of Quad-core Intel processors? If so how? What about having a second, Quad-core processor?Also, what about a dual-graphics card setup? How is this (if at all) utilized in CS3? Are there any performance advatages? Thanks again. Your article/blog really helps to shed some light on a fairly complex issue. I appreciate it.[Photoshop will take advantage of as many cores are in a machine. However… not all operations are threadable, and even for those that are, there are diminishing returns – most of which depend on operating system overhead for threading APIs and memory bandwidth available in the system – that means the performance improvement going from 2 cores to 4 isn’t 2x expect for increasingly rare cases (e.g., Radial Blur is a perennial favorite way of pegging all the cores in a machine at once). As always, we are looking at ways of more fully utilizing all that power. – Scott]

  43. deebs says:

    Isn’t this closely related to the hoary old chestnut of: something at the peak of it’s evolutionary tree (eg 32 bit OS) tends to be more reliable than a quantum leap to a new evolutionary tree (eg 64 bit OS)?Most parties (software, application development, hardware, chip manufacturers, … ) are comfortable to excellent in catering for 32 bit stuff. On the other hand, 64 bit has yet to evolve and become manifest?[Yes, things are still a little green. I hope that changes rapidly over the coming year. – Scott]

  44. beek91355 says:

    I’ve been a long time PS user.I just built a new computer with Vista Ultimate 64bit. Thanks for the clear info on the status of 64bit as it relates to Adobe. I presume that this approach will be followed with all of the their products.Since 64bit capability is going to waste on all of these new computers we consumers need to be heard by all vendors not just Adobe. I know that Canon and Epson have come out with 64 bit drivers for my printers which makes my 64bit OS a little less problematical.[Note that once you can switch to the 64-bit version of the operating system (and have stable drivers for it) that a lot of the capability of the machine can get used at that point – most notably the capability of utilizing more than 4GB of RAM. An individual 32-bit application may not be able to directly address more, but the aggressive file-caching in Vista x64 and OS X 10.4 allow for a good deal of benefit to still be had from having more than 6GB of RAM installed – if you are dealing with images that large. I’ve been running 64-bit XP and Vista for over a year, so I hear you on the driver problem. – Scott]

  45. hosch says:

    I was briefly (approximately 2 years) a programmer before entering the artistic world professionally and the points you make concerning memory and other issues of the sort seem sound wisdom on face value with my very limited knowledge on the subject so that is not the thrust of my point.I am coming from merely an end user point of view and I can state that without a doubt that Adobe products are the ONLY hold up of my company converting over to the 64 bit platform.We have done extensive testing with other applications such as 3ds Max regarding 32bit vs 64bit render times and found that the multiple is not just a bit faster, but earth shattering difference in speed difference. For example, one detailed particle flow file took 33 minutes to render in 32 bit format and the same file took 19 seconds to render on a 64 bit system.It is due to external factors like this (not surrounding Adobe products directly) that force us to yearn for 64 bit systems.However, being a small shop (less than 12 members) we can not afford to have 2 computers for each person and Adobe products are an integral part of our work flow at this time.Please consider our needs as customers from the bigger picture when deciding your timeline to release a 64 bit supported system.I realize that there will be some “growing pains” during this time of transition, but until major players such as Adobe get on board other companies such as printer driver developers and other such supporting companies will not justify the expense in my view.If I missed some relevant information regarding this topic please let me know.[Yes, I believe you might have missed something. Adobe Photoshop being a 32-bit application does not prevent you from moving to 64-bit hardware running a 64-bit version of Windows. Photoshop CS2 and Photoshop CS3 run just fine on Window XP and Vista 64-bit versions (yes, I know the support page says it’s certified only on the 32-bit versions, but I personally worked on Windows XP 64-bit edition for part of the Photoshop CS2 and all of the Photoshop CS3 cycle). In fact, they recognize when a machine has a very large amount of memory available and tweak how some operations are done to both use more address space directly (4GB instead of 2GB), and to let the operating system use memory beyond our address space on our behalf. And in the 64-bit version of Vista, the size of that cache is essentially unlimited, meaning that there are performance gains in having more than 6GB RAM in a machine – I’ve had Vista essentially using ~10GB on Photoshop’s behalf on a machine with 16GB in it. This, and other reasons, are why a fully 64-bit version of Photoshop may not end up with any performance benefit at all over the 32-bit version. The only things that absolutely have to be 64-bit when you wan to move to a 64-bit version of Windows are drivers – so I don’t think Photoshop remaining 32-bit should stop you from moving. – Scott]

  46. Paul says:

    Scott, WOW, how informative. Although half of the info everyone posted was in French, I enjoyed reading all the posts. Where do I start… I am not a programer or code genius. I do use CS2 everyday. Primarily PS and Illustrator, I dabble in Flash and Image ready when the time calls for it. PS files range from 100k to an occasional 100+layer 1G+. PC platform, I never used a Mac. I love new tecnology which got me where I am today. 3 year business owner of a local GFX design studio for print and web. I have good hands on experience building all my own PC’s for work and play as I have built about 5 in the past 3 years. Someone posted a comment about the Task Manager not showing the memory has cleared once large PS files are closed resulting in the need to restart PS. I encounter this same problem when working with large multi-layered PS files and trying to save my work and then receiving the “Not Enough Memory” message. Forcing me to close the file only to lose the last few edits I made. Without closing PS and viewing the task manager, it shows the memory highly consumed for the PS application. Without restarting PS I re-open the file and still cannot re-save the file after minor edits. So the only recourse is a PS restart. Has only happened a few dozen of times that I recall. I Googled the topic to find help, results were to lower this, and raise that, (referring to PS setting) and do the XP-Pro 3GB fix, etc. All easy for me to understand and try but I found this I useless. Can you Explain this? You said there is no need to restart PS in this event? I find this not true.[Lowering the memory percentage Photoshop uses in the Performance preferences panel should have helped here. You need to restart Photoshop for the adjusted percentage to take effect. Keep adjusting down 10% at a time until you find a setting that allows you to save, though we try and use very little memory while saving files to avoid this kind of problem. -Scott]I can hardly find any usefull information out there on this: If I buy a “top-of-the-line” $1500 ATI Fire GL VC, will this boost my PS and Illustrator workflow and on screen performance? ATI website makes reference to CAD but mentions nothing about PS and ILL. Any info on this will be helpfull. I currently run Intel 2.4 Dual Core, GIGABYTE GA-965G Mobo, 4x1GB CORSAIR 6400C4 XMS/Ram, ATI 1600Pro, 2 500GB WD Raid 0, XP Pro.[The display card has very little effect on Photoshop performance, since Photoshop is mostly a 2D application. If you upgrade to Photoshop CS3 Extended and plan to use the 3D features, then the display card will matter. -Scott]Scott, you also posted you recommend 6GB Ram to someone, it seemed you were referring to XP Pro 32bit OS. It this possible? I thought 4GB was max?With 4GB max and utilizing the Windows 3GB switch can I set PS to 100% Memory/Ram? When PS sees the 2GB of the 3GB? And what Cache software are you guys talking about?[Yes, with a 32-bit version of Windows, 4GB is the maximum that you can install in the machine and have Windows recognize it. I can’t recommend the /3GB switch because some drivers become instable with that switch on. You may still not be able to run with 100% because that 2GB limit is an address space limit – computer sciency thing – that means memory allocation can fail even if there is free RAM on the machine. The cache we talk about is the system file cache – the OS itself tries to keep data recently written to disk in memory as well for faster reading, and will use memory beyond what is available for applications. -Scott]I think when talking about 32bit OS and 64bit OS, 4GB Ram, 6GB Ram, 16GB Ram, we are getting ahead of our right now problems when it comes to PS. The bottle neck is in the hard drives of today. All technology is getting faster, but IMO hard drives are falling behind more and more. The need for onboard system RAM is here for a 64bit OS, but we are in a “reality” 32bit world for years to come. 64bit OS does not seem to be the catch-all fix for 1G+ PS files all together. There is some reference earlier to HD technology. I am specifically calling out to Solid State Disk technology. Tell me if I am wrong here Scott, but if I can load a 1+GB file from the SSD faster that any 6 disk Raid 0 WD 10k raptor config, or even a multi drive SCSI Raid 0 15k config, that would be great! Right? Furthermore let PS use the SSD as a scratch disk, when SSD is DDR RAM, seen as a normal HD! WOW! So to recap SSD allows PS to read and write files at record RAM speeds, and at the same time PS uses the SSD normally as a scratch disk but at RAM speeds?!Please tell me if I am wrong, for about a $4490 hardware upgrade to a 16GB SSD or for a 32GB SSD $12730, this can be achieved, right? If you have never seen this, your in for a treat… http://www.hyperossystems.co.uk/“I’ll take 4 of those please!”This looks like its worth $4490 if it will do what I think it will. What do you say?Scott please reply in grave detail to all my questions and speak baby-talk when ever possible. C++ GUI talk is Russian to me. I look forward to a response. ty in advance! Paul.[There are two types of solid state storage. RAM disks, basically PCI cards with lots of extra RAM on them, would indeed be a lot faster than any RAID array available. Those are pretty expensive, though, in the price ranges you noted. Flash memory based solid state disks will end up being a lot cheaper, but their read and write bandwidth isn’t any better than a fast hard drive at this point, and they are still more expensive. If money is no object, those PCI RAM disks for use by Photoshop for scratch would certainly be the way of getting the fastest Photoshop machine possible. However, a RAID box currently provides the best value. We’ll keep watching for flash memory based solid state drives to come down in price, though without a major leap in speed, you would still want to RAID them together. -Scott]

  47. drc says:

    Hi there is a discussion on C__ and scientific computing in particular the issue of 64-bit support it would be interesting to hear your current views.http://www.macresearch.org/carbon_and_scientific_applications

  48. drc says:

    Hi,Thanks for your contribution to the MacResearch article (http://www.macresearch.org/hot_topic_carbon_and_scientific_applications).I see it has already generated a question 🙂

  49. VichCarson says:

    I’ve been a business applications programmer and network planner – so I’m no Systems architect but the explanations you’ve offered have made sense – and raise a few questions and skepticisms in my mind.This last poster’s comment of how another rendering software went from 33 minutes to 18 seconds does shed a different light on your arguments. Mainly; I wonder if you’ve prematurely dismissed some corners of huge performance potential that may REALLY make a difference.You’ve repeatedly touched on a few things regarding 64 bit OS.1. Vastly more registers and thread capacity not present in the 32 bit OS.2. Additional CPU instructions not available to the 32 bit OS (did I misunderstand this?).3. Memory backplane bandwidth as the main limiting factor.4. Not to under-estimate the gain of WOW64 caching advantages available with today’s Adobe.[And, we have done a bit of performance testing on our low-level processing routines which have been tweaked and tuned over many years. Untweaked code tends to be where the biggest gains are, and starts to approach the performance of our tweaked code. Our tweaked code is already fast and didn’t see much, if any, gain. That may not be the whole story, so I won’t assume we know the answer. -Scott]As a Lightroom and CS2 user, I have to say that once in a single photo, everything is so fast that any improvement would be a luxury. However; I’ve mainly noticed impatience during startup, export, and anything that deals with multiple images. I don’t use the 3D aspects and mainly stick to 8MB RAW files (Lightroom) and 4MB JPG files, so I’m no power user by any means.An earlier poster suggested that you could all but eliminate latencies related to multi-processor utilization (during an multi-image Export or Import) by starting a new thread for each file being processed. You seemed to sort of dismiss it as “oh sure, maybe sometimes …”. I believe he really hit on something. I read it as “Adobe doesn’t want to make basic architecture changes to take advantage of multi processing when entirely different processes are occurring”. Indeed, wouldn’t that poster be correct that you could eliminate the latency issues by running multiple photos simultaneously? Indeed; if there are 4 CPU Cores at your disposal and you have 100 images to process, then assigning each image to one core at a time would seem a natural.[I think you read it the wrong way, then. I wrote it as “yes, it’s a good idea, and we’ll make continuous improvements to our code until we get there”. Photoshop is a pretty big app and such changes take a while. – Scott]Your answer to that poster was that memory bandwidth is the real issue. Indeed; that memory bandwidth is why you don’t think GPUs are advantageous either.I propose that when memory bandwidth gets targeted as the bottleneck (at Intel etc), that tomorrow’s computers will double or triple that bandwidth – or take measures to mitigate that issue (embedded subprocessors, more onboard L1/L2 cache, etc). Then you will be left without the reason (excuse?) for not doing upgrades but 2 years of development away from making advantage of the bandwidth. I have to wonder if the 4MB L2 Cache on Intel Xeon processors isn’t a leap in that direction.[Oh, I hope that memory bandwidth gets that kind of attention. We’ll be ready for it. -Scott]2nd nagging question. You mentioned that 64 bit systems have more instructions (at the CPU level). It sure seems a natural for MS to open some of that advantage up to the 32 bit OS. I’m guessing some of those new instructions are graphics oriented (ie: onboard GPU), so instead of your program or the OS sending 1000 CPU calls to accomplish something fundamental, it would make 2 or 3 calls and the CPU would spit back the answer – or perhaps a rendered tile. So; the memory bus isn’t taxed with all the back-n-forth. That’s obviously not in your (Adobe’s) court at this time, but do you see that forthcoming? Is that the sort of stuff that a 64 bit Adobe product could do with today’s 64 bit processors? Would that explain the 33 minute render being reduced to 18 seconds?[Ah, something that takes 1000 instructions to transform a tiny bit of data into a tiny bit of data is CPU bound, and those kinds of tasks can see big, big wins. Color correcting an image is more about reading and writing a bunch of data, doing simple operations on each pixel. -Scott]As a side note: You mentioned that Photoshop CS2 works great on WOW64. Is that true with all the Adobe CS suite as well as Lightroom 1.1?[The other products will work on 64-bit Windows, but because of Photoshop handling it’s own VM (so that you can work with images / layers / history that take up more than 2GB) it’s in a special position of getting the OS to use more RAM on it’s behalf as part of reading and writing that VM. I do think just being on a 64-bit version of Windows provides some speed advantages for all applications, though. -Scott]Oh; and thank you so much for your in-depth attention to this subject. It is highly enlightening and informative. You’ve really cut to the meat of the topic. More importantly to me – it was instrumental to me in placing an order for a XP Pro 64 computer yesterday. 🙂[I hope you are enjoying your new machine. I’ve been running Windows XP Pro 64-bit for a few years now, and Windows Vista 64-bit more recently, and I think the number of missing drivers is now small enough that most folks should be OK switching. -Scott]

  50. hiroaki says:

    Sir,Our office is buying a dual quadcore workstation with Windows Vista 64-bit, and the CS3 Production Premium package.Regardless of the fact that 64-bit may not be necessary, will the Adobe programs work flawlessly on this workstation?Thank you very much for the valuable information being posted here…[I can’t vouch for flawlessly, because no program is flawless, but a significant amount of testing was done using the 64-bit version of the operating systems, and I’ve been developing on a 64-bit version of Windows for a few years. As far as I know, we have no issues that are specific to running on the 64-bit version of the OS. -Scott]

  51. rjs_boy says:

    Throughout the responses here you continue to mention memory bandwidth limitations. More and more systems are beginning to support NUMA. Is memory bandwidth limitations any less restrictive on NUMA capable systems?[Yes, but… An application needs to be made NUMA aware, and needs to have a lot of work done on it to remember and manage the correlations between which processor something is going to run on and what piece of data it’s going to deal with. That’s a stunning amount of complexity to add to a program, and even then there are still going to be a lot of times where the data a thread needs isn’t “close” to the processor that thread is running on, so it’s not clear how much of a real-world win is possible. I know idealized memory bandwidth benchmarks show a big win, but I’m just not sure how well that would apply to Photoshop. -Scott]

  52. jrichard046 says:

    I have a question related to Photoshop CS3 and Citrix Presentation Server 4.5…I already know I can get this to run in our current Farm, but should I is the question I have? What are the CONS of doing so besides the fact that Photoshop eats up the memory of the server? Thanks.[Beyond the memory question would be the latency question – if someone is doing serious retouching work or masking work, working that way would just kill perceived performance. Also, for tablet users, I think you’ll lose pressure information. Plus, I’m not aware of any server solution that does the right thing with monitor color management. -Scott]

  53. DharmaSoldat says:

    I’m looking at buying a new system, and was wondering how much of an impact a video card has on the whole arrangement, aside from being able to effectively drive the monitor i’ll be using.I’m going to be running photoshop as well as flash on my system and wondered if you could shed some light on this for me.Also, overclocking my system to get the maximum push out of the ram… in my best interests to invest time and possibly money in it?[For most Photoshop work, the video card will have little impact on performance. We have seen extreme cases in rack-mount server systems where the on-board video was so slow it actually mattered, but for the most part it won’t. If, however, you use the new 3D capabilities in Photoshop Extended, then video card performance is pretty important, but it’s not necessary to get something super-fancy. As for overclocking… I personally wouldn’t do it, because it’s all about pushing things to where they “fail”, then backing off. How do you know you backed off enough and didn’t just hide the most obvious failures? Those kinds of issues are fine if running games or other things where there’s not a lot of data to lose if things go bad, but when running Photoshop? – Scott]

  54. Esoen Harlinn says:

    As far as I know Windows 2003 server r2 is the most important 64-bit version for Windows. Why on earth can’t I install the CS3 versions of photoshop and illustrator on this platform?CS2 works just fine.[Because, frankly, our installers took a bit of a step backwards. We do install on Windows XP Professional x64, and it took effort to make sure that still happened. I would argue, though, that Windows Vista x64 is the most important version, as it brings much more equivalence to the x64 side of things, especially in terms of drivers, and it can use large amounts of memory more effectively. Note that Windows Server 2008 (currently publicly available for testing from Microsoft) seems to sneak by the version checking, though it obviously won’t be considered a “supported” platform. If you can’t change OS versions, you should be able to get a refund by calling Customer Support. -Scott]

  55. Kipp says:

    Scott, I have a question related to Windows Vista Ultimate 64 bit and Photoshop CS3 memory management. I have a workstation with 16GB of RAM and my understanding is that Windows Vista will automatically use caching or virtual memory before CS3 starts swapping to scratch disks. Is this correct? I thought that I had read above and other places online that CS3 would automatically enable VM buffering and Windows Vista would use RAM above 4GB before CS3 starts using the designated scratch disks (I found a comment online by Russel Williams from Adobe, “So on Windows, you’re all set. Vista in particular seems to do great with lots of RAM (better than XP). Just load up your box with lots ‘o RAM and either CS2 or CS3 will work great.” See link http://www.prodig.org/index.php/2007/04/20/ram-can-photoshop-cs3-cope/). My hope is that having 16GB of memory will keep CS3 from needing to swap to scratch disks and therefore keep performance relatively high. Is this how Windows Vista manages the caching or does the caching work less like a “RAM scratch disk” and more like a buffer for the actual scratch disk? Also, is there some way for me to monitor this in Windows Vista to verify that this is working correctly? When I attempted to open a 4GB file, it opens quickly until it is about 2/3 open, then slows to a crawl. I suspect that it slows when CS3 runs out of 32 bit addressable RAM. I also checked the disk and RAM monitors in Vista and CS3 seems to be hitting the scratch disk even though 16GB of RAM is available to Windows Vista for VM buffering. Is this what actually should be happening? Do I have something that is not set up correctly? You also mentioned that caching software might improve performance for this type of usage (large files, 64bit system, RAM >4GB), is there a particular caching software you have experience with or could recommend that would work better than Windows Vista? Based on how my system is currently performing, it doesn’t seem that the RAM above 4GB is making much of a difference which is contrary to what I expected. I am working with large files (4GB high resolutio 16bit scans of 8×10 film). I would strongly prefer to scan and edit the image at full resolution and down-res for individual targeted print sizes. Thanks very much for your help on this topic, any guidance (or tech notes) is appreciated. Kipp.[Photoshop is limited in terms of address space, to just about 4GB on Vista x64. So, yes, to the key question, the extra memory beyond that ends up acting like a buffer to the scratch disk. On Vista, it’s a very aggressive buffer. BUT, and this is key, when Photoshop starts to write to the scratch file, we try and expand it to make sure it can hold all we need it to hold. For security purposes, that expansion zeros a bunch of stuff out (not our choice), and we wait. Once expanded, you’ll see the reads/writes get buffered (if you look in Task Manager on the Performance tab, it’s the Cached number – it will grow and Free will shrink). That’s why, if you look at the presentation in my Heavy Lifting entry, you’ll see that we recommend a RAID 0 array for scratch. It really makes the buffering of that extra 12GB of RAM much more effective. We’re gong to continue to work on ways of minimizing the impact of that scratch file expansion so that the buffering is far more effective, stay tuned. -Scott]

  56. rbeekman says:

    I just read your blog and found it very informative. I run Vista 64bit with Adobe PSCS3. While I’m not happy with the lack of a 64bit “certified” version I’ll survive until Adobe, et al, enters the 21st century (or 22nd?). What is really frustrating is the failure of Adobe (FLASH) and Apple (QUICK TIME) to provide 64bit compatible software. As with many PS hobbyist’s I use my computer for multiple tasks that include viewing videos on line. Depending on the website I may or may not be able to play the videos. What’s in store for resolving this problem? There are far more people affected by this than the “relatively small percentage of persons who are using PS exclusively” (to paraphrase your blog). Companies such as EPSON and CANON have produced excellant 64bit drivers/software. ADOBE, APPLE and HP’s record so far ispretty pathetic.[I take it you’re running ‘Internet Explorer (64-bit)’ rather than the 32-bit ‘Internet Explorer’? I tend to stick with the 32-bit version for just those reasons, and a web browser shouldn’t be under any address space pressure that would require using the 64-bit version for anything, and there probably isn’t much performance gained by running the 64-bit version of the browser. I know that the 64-bit version of the Flash Player is being worked on, but unlike drivers where you have to have a 64-bit version of the driver on the 64-bit version of the operating system, for end-user applications you have a choice, and can still run the 32-bit version of the browser until all the plug-ins you need are available in 64-bits. I fully expect that most applications will stay 32-bit for years to come, that there’s really no good reason for most to take the leap, and I think that Internet Explorer was an odd choice to move to 64-bit, more of a proof-of-concept than anything done out of necessity. -Scott]

  57. Martin says:

    Scott, thank you for providing the most exhaustive and interesting resource on Photoshop performance I have ever seen … And thank you for your patience in answering all our comments and questions.That said, I of course also have some questions, mainly trying to sum up some of the info in this thread:1) You seem to favour Vista x64 compared to XP x64, is this due to better driver support or is Vista also better at utilizing memory beyond 4 gig? Any other performance advantage?[Yes! I’m finding (YMMV) that I’m seeing more drivers available for Vista x64 than XP x64. Vista x64 is definitely better and more aggressive at using large amounts of memory to speed things up, and Vista’s SuperFetch is good at getting Photoshop to launch faster. -Scott]2) Would there be any noticeable performance increase to have three drives, one for OS and apps, one for PS scratch and one for images files being used? (as compared to the more common two disk solution where scratch and data reside on the same disk)[I would guess there would be benefit, but we haven’t measured how much. -Scott]3) Am I correct to assume that going from singe to dual core processor mean noticeable Photoshop performance increase, but going from dual to quad core would yield a much smaller increase in performance?[Correct. Diminishing returns. -Scott]4) With your comments on memory bandwidth issues in mind, would Photoshop run faster on a cpu with more onboard cache then one with less cache but higher clock speed?[Depends, of course, on the cache size difference and the clock rate difference and the operations being performed. We haven’t measured things to that level of detail yet, and I don’t have enough of a sense for it to even hazard a guess. – Scott]And then a couple of questions more pertaining to Lightroom then Photoshop … If you feel I better ask someone else, just mention who and I will not pester you on that again … :-)5) In general, if I were to build one kick ass Photoshop computer and one similarily kick assish Lightroom computer, would I need to make any significant different choices for Lightroom?[With Photoshop, I’d weight things more heavily towards getting a RAID 0 set for scratch. With Lightroom, I’d weight things more towards having a RAID 5 or RAID 0+1 set for files. Those are guess though, as we haven’t gotten to that level of detail yet. -Scott]6) It is my understanding that Lightroom does not have its own VM in the same way Photoshop does?[Correct. Non-destructive editing and no layers means there’s no current way to create files larger than application address space. -Scott]7) To me it seem like Lightroom potentially could benefit much more then Photoshop from quad core (and maybe even two quad core cpu:s), much of the cpu cycles seem to be used up doing background creation of previews and similar — that to me sound like activites being much easier to put in separate threads. Does that seem like a fair assumtion?Cheers – Martin[While those activities are easier to put in threads, it doesn’t necessarily mean that Lightroom will better scale to more cores, though that would be the way to bet. I just don’t have any data yet that would back it up either way. The Lightroom folks may, I’ll have to go bug them. Good questions, and sorry I don’t have all the answers – we’ll keep working on it. -Scott]

  58. Vince Fleming says:

    Unfortunately for me, I’m the one use case that would really, really benefit from a 64-bit architecture.When we use Photoshop, we create and edit *very* large images. It creates anywhere between 4 and 8 GB of swap files (in the temp directory) on a WinXP system with 4GB of RAM. A RAID0 for these files is an absolute necessity for us – and even with that it can take quite a while to open/save images.I personally can’t wait until I can build a 64-bit system with 8-16GB of RAM and run a 64-bit Photoshop!!!Cheers,Vince[See the presentation in Heavy Lifting – I think you could get a speed boost by going to a 64-bit system and OS with 8-16GB of RAM now. Yes, you would definitely get even more performance from a 64-bit version of Photoshop. It’ll be up to you to decide if it’s worth it in the short term to upgrade now, though, and with the RAID 0, you’ve definitely got the key speed booster going. – Scott]

  59. fredsky says:

    1) xp64 & vista 64.for what i tested and understand (see the post Kipp — 11:16 AM on October 18, 2007) NONE of this OSes (even with 16GB+ RAM) can open a 4GB file fast. It still hit the scratch disk around 3GB…so why using 16GB ram ?[Because one generally doesn’t just open the file to close it right away, and the extra RAM gets used by the OS to cache reads and writes to the scratch as you work with the file. It’s not as much of a speed boost as having RAID 0 set up for scratch, but it does help when doing multiple operations on a large file. -Scott]2) virtual ram disk. conclusion to point 1 : i wonder if using a software RAM disk of 4GB or more will be more efficient than let the OS manage this RAM ?[Probably not is my guess, as it’s pretty easy to run thorough 4GB of scratch quite quickly, at which point Photoshop would have to use a secondary scratch disk, slowing things back down for the next operation. When used as cache, it will generally hold the most recent bunch of data, which helps with the next operation. -Scott]3) hard disk : only hopes comes from SSD (fastest one like Samsung in SATA2 , write/read @80MB/s), or even better the IO fusion (700MB/s !!!).http://www.fusionio.com/news.html[Yeah, I’d like to get my hands on a ioDrive for testing. -Scott]for now on, does the scratch disk use SEQUENTIAL or RANDOM read/write ? I do wonder why with 10 HDDs seagate 7200.10 in RAID0 with a DELL perc5/e hardware RAID card i only got around 80MB/s ?regards, and so much thanks for such an informative blog :)fredsky[What we’ve found as we looked around on the ‘Net on RAID is that not all RAID cards or motherboard implementations are created equal. I can’t speak specifically to your solution, but we’ve definitely seen a wide range of performance. Photoshop reads/writes in large enough chunks that we should get closer to sequential rates. We’ve only started scratching the surface of RAID and Photoshop scratch performance ourselves, so much of this will be left as an exercise for the reader for now 🙂 -Scott]

  60. fredsky says:

    Hi Scott !I’ve benched a LOT the scratch disk.I written a little script that create a image of 20,000×20,000 pixels, 16bits RGB. size : 2.24GB.then apply a radient and then save as PSB.the results are reproductive :)hardware setup:- my disks are 7200.10 seagate ES 750GB- i got 3 RAID controller (DELL perc5i, DELL perc5e, Areca ARC-1680x)- i got 2 internal disks and 15 exeternal throug DELL MD1000 enclosure- RAID0 always, 64k clusters- OS : win2k3 64bits, 64k NTFS, basic disk.results :best performance is get when using 8 HDDs (raid0).BUT THE mesured throughput of the scratch disk is under 40MB/s !!!with 2 HDDs, more than 20MB/s.more than 8 HDDs will be SLOWER. mean my test with 14Hdds give a little more performance than… 2 Hdds !so there is a HUGE problem of scaling… perharps access time is the bottleneck ?so far, I do think that using a fast SSD (like MTRON one) will give you much more speed. can you confirm this ?cheers,fredsky[Scaling for RAID is going to be highly dependent on the RAID card itself. I’d most will scale to 4. Beyond that will take a server class RAID card. As for the MTron, we’re still waiting to get our hands on something we can test. We’ll update things once we know more. -Scott]

  61. Obelisk Moonprattle says:

    Very useful article. I am about to replace my 4 year old system and am finding the current situation difficult to sort out. To make sure I understand, although it will not improve performance, I should be able to run CS3 on a Vista Ultimate 64 bit platform with no problems? Is that correct?[Ah, but it will help with performance. Photoshop CS3 on Vista x64 has access to more of it’s address space – almost 4GB – as opposed to just 2GB on the 32-bit version of the OS. Yes, Photoshop CS3 should run on Vista x64 with no additional problems itself, but you may still have a hard time finding drivers for legacy equipment. -Scott]

  62. fredsky says:

    hi scott !you wrote :”Scaling for RAID is going to be highly dependent on the RAID card itself. I’d most will scale to 4. Beyond that will take a server class RAID card.”i’m sorry, but the Perc and especially Areca ARE one of the best SERVER class RAID card available.so, for me, the scratch is use a lot of random IOPS. that why very fast access drives or SSD are the key to performance.[I don’t have enough experience with specific RAID cards to know, so we’ll take your word for it on those two cards. Photoshop’s scratch access is in fairly large contiguous blocks – over 100KB each – so sustained I/O bandwidth is as important as seek time. We’re still trying to get an SSD based scratch system together. I’d contend that it still needs to be RAID to get the performance wanted as current SSDs still top out at 100MB/sec write individually. -Scott]

  63. Shan says:

    Scott, you must come to a realization that x64 has arrived and is here to stay. Your arguments for not supporting an x64 version of Photoshop are very weak, and the end result is that ignoring 64-bits for any longer will put Adobe further behind. This industry is littered with vendors that had the exact same approach in the past to newer technologies than you are demonstrating in your blog – and many of those vendors are no longer with us or have lost their technical leadership. I for one am using Vista x64 and have all the drivers I need. I would benefit from a 64-bit version of PS and would welcome a change in attitude from Adobe on this. Please reconsider your approach for the benefit of your current and future customers.[I hear you. -Scott]

  64. Crunch says:

    I would also like to purchase an x64 version of Adobeshop CS3. This is going on being a 2-year blog, and nothing has been done? I agree that XP x64 is a joke, and really never took off, but Microsoft was smart by releasing both x86 and x64 versions at the same time. The W-o-W layer also makes running x86 applications a breeze. But native x64 apps are still much preferred, and very much Internet browsers!Which brings me to my other question: Why is taking Adobe so long in releasing at least the Flash player plug-in?? Ideally Shockwave, too, but Flash. A plug-in. Come on…?? When you guys kick the RTM SP1 back out to Microsoft, will it include the plug-in at long last?Please tell me good news, or at least an approximate ETA.Thank you.Regards![Photoshop is a rather complex and large application, so doing anything as foundational as moving from 32-bit to 64-bit addressing takes time. More news will come soon. -Scott]

  65. RvDam says:

    Is it still wise to upgrade my PC from 2Gb to 4Gb or is the performance change not noticeable. I’m using Windows XP 32-bit and will upgrade my PC to Vista as soon as the service pack is available.[There are issues to be aware of with Windows XP 32-bit and more than 3GB of memory, some of which can be motherboard limitations, some of when are due to video card address space mapping. I would only go to 3GB RAM myself in that situation. If the files you are dealing with are large enough (say, you have 20 50MB files open at once, or a few files with 100 layers), you would probably see a performance difference. I can’t say if that it would be worth it, though, as it really depends on your specific situation. -Scott]

  66. I have a client with a new HP with a Quad Core Processor, 3GB DDR2, 8400GS 256MB card and a Sata-300 drive, Vista Home Premium. The complaint is that PS is slow, and thought the HP was a lemon! While researching what hardware addtions/upgrades they would need I found this blog.Here are the items I am considering selling my client:1.) Gigabyte GC-RAMDISK i-RAM 4 GB Hard Drive or PCI Raid 0 Card with 2 7200/10,000RPM Drives2.)Geforce 9600GT 512MB3.)CS3 and Vista Ultimate 64I was hoping that 1 and 2 would be a seat of the pants improvement, and 3 would most likely require an new PC as I don’t think the motherboard can handle more than 8GB of ram.What do you think Scott?[I think I’d skip the i-RAM – it’s too small to do any good as scratch. I’d also skip the display card update, since it won’t really provide that much benefit to Photoshop, unless they already have Photoshop CS3 Extended and use the 3D functionality extensively.Instead, if they’re operating on large files or files with many layers, then concentrating on the drive situation is the right way to go. In that case, the RAID 0 with 2-4 drives for just Photoshop scratch is the first step. If they are doing a few operations each on a large number of big files, then, in addition, getting the data files off onto a RAID 5 or 0+1 set of 3-4 drives – or an external Drobo box – would get file reading/writing faster, but even one extra drive dedicated to just data files would help.If the motherboard is recent enough and capable, moving to Vista x64 and getting 6GB of RAM in the machine will help. I think 6GB is the current sweet spot for CS3 on Vista x64 – more helps, but with diminishing returns. I’d consider this second priority, behind the RAID 0 for scratch, since the machine currently only has one drive in it. -Scott]

  67. Shan says:

    Adobe announced today that Photoshop CS4 will be 64-bits! Thanks for listening Adobe!I find it interesting that for larger files, the 64-bit version of Photoshop is 10 times the speed, where the initial assessment used by Adobe to avoid porting to 64-bits concluded that the “performance win is very small”.http://www.news.com/8301-13580_3-9909725-39.html?tag=nefd.lede[Yup, I was wrong on that large file guess. I thought that having the OS use the extra memory for file cache would be in the same ballpark as Photoshop having access to it directly. The real result surprised me. Nailed the overall 8-12% guess I had for normal sized files, though (not that I wrote that down anywhere for you to check on me). -Scott]

  68. Graham says:

    I have just installed Vista SP1. Vista (32bit) now shows my 4gb ram but Photoshop shows only 1677MB available ram. I understand from previous post that an application is limited to 2gb but why does PS only see 1677?[The executable and various libraries being used take space from the 2GB of address space visible under a 32-bit OS. That means that by the time we’re started up, there’s less than 2GB left over to use for image tiles. – Scott]

  69. greg_dd says:

    I am sure you are sick of hearing how amazing and thorough your post is but . . . your post is amazing and thorough.My question is when using very large files (1 to 3 GB) and given the limitation on RAM and Bus speeds as noted, do you think that having a dual Xeon Quad core machine would be worth while. So given the limitations of bus speed can photoshop still keep 8 cores busy? The machine would be a Vista x64 with 8 Gb of Ram and two Raid 0 SAS arrays (one for boot and one for scratch).[Keeping 8 cores busy is very hard. There’s only a handful of functions I know that are compute intensive enough to not get bandwidth bound at 4 cores or below – so unless you do Radial Blurs all day or work heavily with 3D or compressing video, it might not be worth it. -Scott]

  70. Kate says:

    Hi Scott, I have to say this has been an excellent informative thread of information, even if I don’t understand 100% of it. But it has helped me to understand my PC and it’s “limitations” I purchased this HP Pavilion DV9000 Core 2 2GBRAM- Vista Ultimate 64bit OS. I have had this Lap top now for 1 Year and of course my Studio 8 dosent run well on it – now I know why! My question is… If I want to upgrade my web dev software, Will Creative Web Premium also be upgraded to run on 64bit OS? and is it also a question of when?[32-bit apps will run on a 64-bit bit OS just fine, and some software can in fact take advantage of having more address space when running on a 64-bit OS, even if they’re 32-bit still. That means applications that don’t need the extra address space probably won’t be made 64-bit any time soon. As for official 64-bit OS support, with Vista x64 now supposedly accounting for 20% of the Vista out there, I’d expect that to happen soon. -Scott]

  71. Øuantum³ says:

    Hello Scott :)I will leave all the personal introduction away and be short, surely, you will love that :)I have a 32 bits Windwos XP with 4GB of RAM (3.4 GHz INTELCPU Cache 2 MB).My question is:Will Photoshop use 3 GB or more RAM if I install X64 OS?Thanks for your reply, in advance :)س[Yes. Adobe Photoshop CS3 is built with a linker switch that tells the Windows operating system that we are >2GB “clean”. That means on Vista x64, Photoshop will have nearly 4GB of address space to work with. I recently installed Vista x64 on a machine at home with 4GB of RAM for just that reason. -Scott]

  72. Jimcecere says:

    I am buying a new computer, would a 64 bit unit be a mistake? I use Adobe creative suite 3 a lot and also pagemaker (don’t yell)ThanksJimjames.cecere@gmail.com[At this point in time, I highly recommend going with a 64-bit machine (all Macs and most PCs at this point are 64-bit machines – I consider a PC being true 64-bit if it’s got a full 64-bit capable chip set in it; the specs should say that the motherboard supports 8GB RAM or more). And yes, unless you have some very obscure piece of hardware that doesn’t have a Vista x64 driver available, I recommend going with one of the 64-bit editions of Vista on the Windows side. I recently bought a new PC for home, and that’s how I have it set up – 4GB RAM, Vista x64 (Ultimate in my case – but Home Premium will work). -Scott]

  73. TerryLarsen says:

    Scott,We have a new BOXX Technologies 8450 Special Edition workstation. It has two Intel quad core processors running at 4Ghz (8 cores total), with one 15K RPM perpendicular drive for the OS, one 15K RPM perpendicular drive as a Scratch disk and a 1.5Tb RAID5 array for storage. It has 16Gb (sixteen Gb) of RAM and an nVidia Quadro FX 5600 video card with dual monitors.It will be used for Maya 3D modeling, Premiere Pro video editing, Encore DVD authoring, Photoshop image composition & Illustrator drawing.Can I safely run Adobe CS3 Production Premium on it with Vista Ultimate 64?I understand you are a Photoshop man, but wondered if you have ventured into the Premiere Pro and Encore world. (We use all of the Production Premium products.)Some forums are stating problems with Encore not recognizing the DVD burners. Are there known issues I should be aware of before installing Adobe CS3 Production Premium on the BOXX workstation with Vista Ultimate 64?Thanks for your time and knowledge in this blog.[I don’t get a chance to use our other products here at work – a little busy for that 😉 – and I just got a new Vista x64 machine at home and haven’t had time to get to any DVD burning. I would imagine that for the most part the CS3 suite will fly on that machine, but I can believe that with the new drivers required for Vista x64 that there might be some glitches here or there. I’ll keep an ear out, but since I’m not deeply involved with those products, you’ll probably be able to get answers just as fast as I. -Scott]

  74. Jamie says:

    First off I am far from a computer wizard . I just bought a new computer with windows vista home premium with a 64 bit system. I bought Photoshop 6.0 and after 45minutes one day and an hour and a half the next with adobe tech support they said the reason I couldn’t even load it was because of the 64 bit system. They are working on a refund at any rate. I am not a professional photographer so I don’t see the need to buy the CS3 that is compatible for $600. I do want a good editing software though. My question is were they correct with the 6.0 not being compatible and is 7.0 going to be the same? If so what editing software should I get since the boxes say nothing about 32bit or 64bit? This is frustrating for those of us that are not the tech type. Thank You![I’m sorry for your frustration, and I do hope customer service gets you that refund.Visiting one of my favorite Photoshop sites, PhotoshopNews, I looked up our release dates in the Splash Screens list on the front page. Photoshop 6.0 was released in late 2000. That’s before XP, much less Vista or Vista x64, so while I would hope that it would work, I’m not terribly shocked that it doesn’t work. We can’t predict the future, nor can those making the operating systems, so while we try and obey the operating system rules so that future operating systems can still run the application, and the operating system vendors try and remain backwards compatible with older applications – well, it doesn’t always work. KindaHave you taken a look at Photoshop Elements? It’s much less expensive, and almost certainly has everything you need. Or, if that’s even too much, there’s Photoshop Express online. -Scott]

  75. Scott Schaus says:

    I’m considering a Vista 64-bit Dell Precision and understand the recently-released CS4 will perform nicely in this environment. However, Framemaker 8.x is listed as not compatible–does this imply it won’t run at all, or that I will have to run it in 32-bit compatibility mode? Thanks.[Unfortunately, I don’t know. I found http://www.adobe.com/go/kb403291 which doesn’t help one way or the other. I’d be surprised if it didn’t run, but I wouldn’t stake any money on that. I would check the trial version, which you can get to from http://www.adobe.com/products/ before putting any money into it. -Scott]

  76. My company is video production company. We recently purchased Adobe CS3 Production Premium and run it on an HP m9160f 64 bit machine and Vista Home Premium 64-bit version. It is killer!!! I have had no problems (other than this one) with either the machine, the operating system or Adobe CS3. I can run premiere pro, after Effects and Flash at the same time with absolutely no degradation in performance. The system has NEVER crashed.Having said all that, please please please complete the work on the player for the 64 bit explorer browser. It is a a real time waster not having this capability.CS3/4 production premium on a 64 bit system will eat Final Cut Pro for dinner and take over as the industry standard. But please fix this problem so I can really brag about the capabilities my company has with this new technology.Thanks[I hear you on the browser plug-in. Others have heard it, too. -Scott]

  77. Leon Kendrick says:

    I have a HP m7690n desktop currently with 2GB of RAM with an Intel 2.13 GhZ dual core processor. running Windows XP Media Center Edition. I have 2-250GB internal non-RAID hard drives,with a 500GB HP Media Drive that slides inside the case. My graphics card in a NVIDIA 256MB GeForce 7600 GTHere’s my question. I would like to install the beta of Windows 7 and be able to run LR and CS3 in both XP and Windows 7. I plan to purchase CS4 soon to see how it performs in both environments as well.I primarily use this machine for Lightroom and Photoshop work. I also use it for some related internet work and viewing emails with MS OutlookMy plan is to format both internal drives, partition drive 1 to have XP and Windows 7 on one partition, applications and data on a second partition on drive one. Drive 2 would partitioned for a Photoshop scratch disk, a small partition for page files, and the rest for backup for drive 1. The HP Media Drive would be backup for drives 1 and 2.Obviously, another option is to put XP and drive 1 and Windows 7 on drive 2 and use the Media drive for backup.Any suggestions on which option would be better for CS4 or a entirely differently option?Thanks.Leon[I highly recommend that you install Windows 7 to a separate partition than XP is on. Having two Windows installs on the same partition can be dangerous. My suggestion – and I honestly don’t know if this really would work better, but it’s my best guess – would be to have three partitions on the first disk, one for each OS and their paging file, the third for applications and data. One of the things I’m trying to avoid with that is having the system paging file(s) on the same physical disk as Photoshop scratch. And, avoiding anything that needs the best I/O performance (OS, paging, scratch) on the insertable drive (which is USB2). Also, I like to avoid having two OSes point at the same partition for paging files, even though it costs some disk space. Just part of my don’t-let-two-OSes-collide paranoia. Especially with one of them being a beta. -Scott]