I see a lot of people suggest the GTX5XX for the mac pro. I was loooking at a GTX570 myself, but realized that the Radeon HD7850 for instance seemed to be at least as fast, used less power, and for a lesser price had more memory (depending on your country of purchase and the exact type of course). I wanted to stick to a GTX for cuda, but just read that in fact Photoshop Cs6 new engine does not rely on it ! If EFI boot screen is not a must, is there any advantage to use a GTX5XX vs a Radeon of similar performance ? I also use vray for Cinema4d for my rendering, but sadly the current version is not taking advantage of GPU acceleration - but that may change in the future and then one platform may be preferred over the other.