We are using CS5 on Mac OS X 10.6.8 with a Mac Pro 2x2.93GHZ 6 Core Intel Xeon (the latest and best Mac Pro that Apple offers). We have 32GB of RAM and are using an ATI 5870 HD video card running two monitors (Original Apple 30inch display and a small LG for palettes). Fast SSD boot drive and scratch.
We have an issue were after we convert from RGB to CMYK (or even sometimes just viewing in CMYK) the screen slows to a crawl and a lot of times it will crash. In RGB mode it's perfect but once we are in the final stages of prepping files for our clients (Ad Agencies) we normally flatten the image and make sure the ink levels are where they are supposed to be. Our files are generally around 400-500MB flat.
As soon as we convert from a flat RGB file to CMYK it will slow down the main display (Apple Monitor) and it appears that the video card/drivers are having trouble outputting to the screen as it refreshes it. If we move our cursor over the areas that are having trouble it will usually update that portion of the screen but if we didn't move the cursor it would just appear mid res. Other times (depends on image) it will just crash with a spinning beach ball (we have left if for hours and it never recovers).
Not sure what to do here. We have two of these machines that are configured EXACTLY hardware and software wise and it happens on both. Does anyone have any suggestions? We have used different settings in the history and cache and they are all fail to provide a resolution to this serious problem. Does anyone else have issues like this?
First make sure you have all the Photoshop updates installed.
If that doesn't solve it, then try turning off OpenGL drawing. It sounds like the video card is having trouble managing resources between Photoshop and the dual displays.
We have done this and it's slightly better but still very slow. Will continue to test it.