Well, bad news for me.
Seems I'm CPU limited with my 3770k @ 4.4ghz.
I can't maintain 120fps. It dips down into the 70's in some spots. High or Low graphics changes nothing, CPU is pegged at 25% (basically 2 threads) and my overclocked 7970 is hovering at 40% usage.
Game is fun either way. Just a bit disappointed by this performance.
Since you're using an AMD card, if you have PhysX enabled that would be why. PhysX just doesn't seem to work well on software-emulation run on the CPU.