I've been researching workstations, Photoshop may not fully utilize the processor but it shouldn't it benefit from the video cards?
Reviews may show Apple being the best computer for Photography but your typical store bought systems (PC or Mac) comes with what I call a "Consumer" grade video card. Even Nvidia has stated their general video cards don't function with Photoshop and recommend their "Professional" video cards...cards not found in general consumer computers in stores including the Apple store. The only machines I've found thus far that comes with a decent professional video card has been workstations. Unless you custom build one.
Well. I have a K2000, which is the first tier in the Quadro K-series, so I don't really know. Not a whole lot is known about AMD cards in the Mac Pro. I am guessing they are similar to (really over priced) W600. I think that when you hear about the mac pro video cards, you're hearing a lot from people who use consumer cards, and yeah, workstation cards seem pretty weak by comparison if you're looking at the numbers alone. Most of these people haven't used a Mac Pro and think that the sole qualification of a powerful computer is how fast it runs Call of Doodie. Getting good information about workstations online is very difficult. I've found that the internet is heavily polluted with teenagers who have literally no idea what a workstation is.
There is a LOT of debate over consumer versus workstation video cards. For pure number crunching, consumer cards often out-perform workstation cards, and people will often point out that Nvidia's Keplar cards use the same architecture on both GTX and Quadro. However, when testing for OpenGL performance, the Quadros typically out perform the GTX. So, there is something that does differ, whether this is hardware or software doesn't much matter.
I know that Adobe products use CUDA as well as OpenCL, and this *might* be where the consumer Nvidia cards fall short. I've heard that AMD cards work better with Premier, so this would suggest that, at least as far as Premier goes, OpenCL is better optimized.
However, if that is the case AMD cards, both professional and consumer perform very well under OpenCL, so if you don't need the OpenGL viewport it might be better to go with an AMD consumer card - and FirePro cards from AMD likely perform equally well under OpenGL as Nvidia cards do.
If you need a CUDA compute unit, you might be better off getting both a FirePro for display and GTX 900-series (or four) as a the compute nodes. Whether this will realistically improve Photoshop performance is anyone's guess (i have serious doubts). It might just be that Nvidia claims that GTX doesn't run well with Photoshop to convince people that they need a $1500 K5000 when PLENTY of people use $100 GTX 500-series cards with no issue what so ever.
That said, the Mac Pro is a fine machine and has a proven performance record. If you're the type of person who won't likely upgrade and you have thousands of dollars burning a hole in your pocket, it's a good solution - and frankly, no more expensive than similar workstations from HP or Dell. In fact, when you're buying new, non-refurbished units, the Mac Pro is probably one of the less expensive options out there in the very expensive world of workstations.
