I'm fairly certain my hardware (2700k, gtx670, 8gb ram) should be able to run Arkham City with everything on high at 1080p, but I get some random stuttering at times and during the benchmark it drops all the way down to like 15 fps for a few moments. I have everything at high and physx on high - does this happen to anyone else with a fairly top of the line machine?

DX11 has been broken since release. Just run it in DX9.

Okay. Is tessellation the only real difference between DX11 and DX9?

Make sure to uninstall the amd dual core optimiser. It's installed by default with he game. I've had no performance issues in dx11 with everything maxed.

I see the stutters as well, doesn't matter if I have dx11 on or off.

Sad to find out that they never bothered to fix this...What a waste of time.