When moving back and forth between images in the Develop module in Lightroom and in the Camera Raw dialog in Photoshop, it can be a performance advantage to increase the Camera Raw Cache when working with raw files. To do so, in Lightroom, select Preferences > File Handling > Camera Raw Cache Setting and increase the Maximum Size. In Photoshop select Preferences > Camera Raw and increase the Maximum Size. The larger the cache, the greater the number of images Lightroom can hold onto for quick access – making it faster to load recently viewed images. If you are simply moving from one image to the next (without returning to the previously viewed images), then you may not see a benefit from increasing the Camera Raw Cache.