Soldato
From watching Rich play the game game on both the GTX 580's and 7970's the game seems more dependent on the minimum FPS.
As a single 7970 seemed to me very playable, even Rich commentated in his surprise at how smooth it felt. Crossfire 7970 was simply fluid at all times with no issues on play-ability.
Yet the results show both cards to be pretty much neck and neck, a single GTX 580 was getting choppy in areas, I know I noticed it and so did Acemodder. A pair of GTX 580's seemed just like a pair of ATI 7970's, gameplay was fluid, though the ATI seems to have a much better minimum FPS in crossfire compared to SLI. What I did like was a single 7970 remained silent even whilst gaming.
In short from our testing if your looking to buy a new high-end card now then your not going to go wrong with either a 3GB 580 or 7970 they both have great power.
If it was my £400-£450ish I'd be buying a 7970, am sure Rich would be buying a GTX 580.
Wait to see more reviews of 3GB 580 vs 3GB 7970 from other places to really help with your decision and then come and buy from OcUK because we obviously stock both.
Or wait until April/May for NVIDIA's new flagship card.
No offense here but its a dangerous game using the phrase "silent even whilst gaming" when every single review says the complex opposite to that.