I am using a Q8400 @3.8Ghz and a single gtx560ti. In BF3 ultra I am getting an average of 30fps with highs of 48 and lows of 19 (thus high setting for me for smooth gameplay) 30fps is the minimum for a real smooth gameplay a higher fps would mean that when it gets to a low point it wont be as low. but I do prefer playing with 45+ fps. With your faster processor and SLI then you should have at least 60fps on average there but im sure there would be a few dips.