I'm talking about a 6950 not a 6850
what i do get is people say the 5870 is better then the 6950
i guess i havent bought ati in awhile
I prefer getting a single powerful card rather than XFire or SLI since not all games will take advantage of those techs.
The GTX 460 is roughly equal to a HD 6850 so two GTX 460s should be able to easily outperform a single HD 6850; as long as the game uses SLI. Most of the popular title should be able to use XFire or SLI.
I would guess 2GB of VRAM on a 1920 x 1080 monitor is a waste. One a three monitor gaming setup I would say it's required.