Just downloaded the CS5 Master Suite Trial. Here's my Setup: MacPro 1,1 with ATI 4870 Driving a 24" LED ACD (Center) and a 20" ACD (right) AND the original 7300 GT driving another 20" ACD (left). Under Preferences > Performance > GPU Settings, PS is only detecting the much weaker 7300 GT, and not allowing advanced settings/performance of the HD 4870. (Previously, CS4 automatically detects the 4870.) Anyone else with multiple/mixed GPUs having this issue? EDIT: Came across this article on nVidia's site, the wording almost sounds like Photoshop favors nVidia hardware over other brands. I know its not too common to have mixed GPUs in one system, but I know there are other users that do on this forum...anyone....? Bueller?