The PC version of the 8800 GS is a 384mb graphics card. Apple's is 512mb so that doesn't make sense.
It has been known that the 8800GS is really an 8800m GTS or GTX but im not sure of which
You might think its as simple as that, but its not. I have no idea what this card really is, so i have no idea on what drivers to download. Apple only uses mobile graphics cards in their iMacs, and that download is for desktop cards.