There have been quite a few questions lately on various forums about what the maximum image (frame) size is that Premiere Pro can handle.
This confusion is understandable, since there are actually several different limits depending on exactly which kind of image frame you’re talking about, and there were changes to the numbers for Premiere Pro CS5.
The maximum sequence frame size in pixels is 10,240×8,192 (widthxheight). If you attempt to set one of the Frame Size dimensions higher than this limit in the Sequence Settings dialog box, Premiere Pro will reset the value to the maximum.
still image and movie size:
The maximum frame size that can be imported for still images and movies is 256 megapixels, with a maximum dimension of 32,768 pixels in either direction.
For example, an image that is 16,000×16,000 pixels is OK, as is one that is 32,000×8,000, but an image that is 35,000×10,000 pixels can’t be used.
Whether a frame can be processed by the GPU acceleration portion of the Mercury Playback Engine depends on the size of the frame compared to the amount of GPU memory.
To be processed by the GPU acceleration, a frame requires ((widthxheight)/16,384) megabytes.
If that value exceeds the available memory, Premiere Pro will use the CPU only for rendering of the current segment.
This means that some images will not use CUDA acceleration on some cards but will on others.
For example, one image size from a Canon T2i is 5184×3456. Doing the math, this requires 1,094MB, which just exceeds the 1GB available on the Quadro FX 3800, but is still within the 1.5GB of the Quadro FX 4800.