I think there is some weirdness going on now. With the new drivers and DX11 on, I am getting the same performance I was getting with DX9 before these drivers. Everything maxed with physx on high.
The reason I say it is weird, the game doesn't seem to be applying the changes I make to the settings before launching. I lowered the resolution so I could play on my 3dtv, and even though it says 1280x720, it stays locked at 1920x1080 when the game actually launches. Then when I reset to defaults, it goes to 1600x900 I think.
Is there a way to tell if the DX11 stuff is actually working? I'm new to PC gaming so I can't really just look at it and tell. I think it looks pretty amazing with DX11 disabled.