Introduction - AMD 6970/6950 CFX and NVIDIA 580/570 SLI Review | [H]ard|OCP
Enjoyed this read very much.
GTX580/570 SLI & HD 6970/6950 CF on 3-display setups @ 5,760x1200. Most games were averaging between 45~55 FPS. Some games, such as Metro (what else?) demanded so much, resolution was dropped to 1050, even for GTX 580 SLI.
NV cards bottlenecked on DX11 due to limited memory capacity, leading to performance levels below that of the HD 69xxCF. Older DX version games that are more dependent on GPU power and not so much on memory capacity understandably favored the more powerful NV cards.
Conclusion: Nothing

. I won't make that investment in GPUs and monitors until I get the smoothest frame rates. If last year's games can't reach 60FPS @ 1200, then the newer and more demanding ones can only perform lower.
NV needs to increase the mem on their cards and reduce their prices. AMD seems to be on the right path price/performance wise and seem like a better purchase, then again ATI drivers for eyefinity are a nightmare to deal with, primary screen moves around at its own will and some monitors go to sleep, and some profiles are non-existent for new titles. So neither option is good enough for multi displays yet.
On the bright side of things, waiting 1 year for the GTX670SLI and HD 7950CF should get us to smooth gaming @5,760x1200, waiting 2 years for GTX770SLI and HD8950CF should get us to 7680x1600. Hopefully by that time new, cheaper, more efficient display technologies will come around.