Apple, masters of planned (early) obsolescence
Over the years, Apple has show utter disdain for their customers by very often throwing them out in the cold with updates targeted to hardware as little as 1 year old, and sometimes even less. For example, with the advent of Quartz extreme some years ago, Apple shut out users with relatively recent graphics cards, without bothering to at least secure any third party sources for reasonable replacement cards. Back then, the only "sanctioned" option for my G4 was to buy an ATI 9800 for an exorbitant price (I believe it was about $250-300.) I had already replaced the graphics card once, and that card was 8 mo. old.
True, that OS (10.2) worked on my machine, but without hardware acceleration, the new OS used the CPU for drawing the screen, and slowed way down accordingly. So Apple could say that it was compatible, they just never mentioned if it would be practical.
Thanks Apple, once again, for deciding that a 1 year old computer does not deserve to be compatible with new OS requirements. I have an 8 core "early 2008" Mac Pro, with the standard ATI Radeon HD 2600 XT graphics card. It seems that this card is not able to take advantage of OpenCL. Not as bad a slap as the example above, but still - it seems that Apple can't be bothered writing a few extra drivers . . .
Oh, I'm sorry, isn't this clear in their press releases?
From Apple's site http://www.apple.com/macosx/specs.html :
> * NVIDIA Geforce 8600M GT, GeForce 8800 GT, GeForce 8800 GTS, Geforce 9400M, >GeForce 9600M GT, GeForce GT 120, GeForce GT 130.
> * ATI Radeon 4850, Radeon 4870
Yes, 10.6 will work with this Mac, but it won't be able to use OpenCL unless I "upgrade" to another video card priced anywhere from 2 to 4 times the equivalent price for the exact (except for rom) PC equivalent . . . if you can find one at all.
Want to get a new card from Apple? The only one they offer is the ATI 4870 for - get this - $350! And this "Mac" version only has 1 DVI port, in addition to a totally useless Apple "mini display" port.
Way to go Apple. No, really, Apple, just go . . .