I had similar issues with low framerates (with a GTX 680 and i7 950), but finally found that the view distance for objects is the real FPS killer, like someone else said earlier.
If you still can't hit 60+ FPS no matter what you do, turn the overall view distance all the way down, the shadow view distance barely affects my FPS. That's just to show you how high your FPS can really get should be almost over 100. Now, to fine tune it, you have to set overall to max, then move the object view distance down until you are at your favored FPS. Let me know if this helps anyone!
A problem that I'm about to post in it's own thread (unless I find someone with a similar problem) is that weird visual artifacts/glitches get much more common the lower the object view distance gets. Just an FYI.
