Same for me on my HTPC with a GTS 450. Win x64. Rolled back to 285.38 and all good again. Poor effort Nvidia.
I am running 120hz and seriously… I should have to constantly be disabling crossfire depending on which game I choose to play.. fail AMD.
Mine is also broken. I have 3x6950 and I cant even get the game to take DX11 and only get 17-22 FPS.
Disable X-fire and in DX11 all turnned up...