I'm having the same issue, 2 580GTX in SLI. Did you fixed it?
I have the 331.65 drivers. Even If I turn everything to normal, the stutter is still there, so I'm guessing is an SLI issue, not that my cards can't handle it.
I was having this issue with a 670 even if I put it on Low settings. I know it's been said a ton already, but after upgrading to Windows 8/8.1, it fixed it and I'm at ~90fps now on Ultra settings. Upgrade if you can!