Originally posted by: GhandiInstinct
Just buy an ati card and be done with it.
It's not that simple, I need to decide what is more valuable, HDR or 3Dc?
So I'm curious what owners of both cards would have to say, but not many on this thread
HDR is a better feature then 3Dc - dynamic lighting is something that's becoming raved about in most future games, where as most developers don't seem so bothered about 3Dc (essentially slightly better texture compression). That's not to say 3Dc won't be used or become standard, it just won't have that big an impact. For some but not all games the hdr performance hit will be too high for you to use it with a 6800gt, particuarly if you game at a very high res. The other big feature game developers are raving about is parallax mapping (also known as virtual displacement mapping), despite what some have said all cards support that (even FX's and 9800's) but only the newer cards have the grunt to use it. There's also true displacement mapping which only a 6800GT supports (part of SM3 I think) but it doesn't have the grunt to use it, even a 7800 would be too slow for that.
SM3 is more likely to be supported in future games an it's quite probable that at some point developers will stop bothering to support SM2b because it's not worth the effort to write a specific render for it (they'll just write an SM2 path because that supports a lot more cards). Hence 6800GT is likely to get a performance boost over X800 cards in the future.
Bottom line is cost - if you can find a great deal on any of the cards mentioned then get it, if prices are similar 6800GT is the best bet. It will probably have the highest resale value as well (because when you sell it prospective buyers are going to care about SM3 and hdr support).