So you want me to test a single gpu? I'm confused, i thought the issue was gpu usage in Crossfire? I just copied your settings and drove around for 5 minutes in full screen mode with Vsync on, very smooth. Fps was locked at 60FPS constantly on the 7990 and gpu usage was around 40% per gpu. I recorded the gameplay too, but watching it back it seems to exhibit a weird recording stutter that was not present whilst i was playing.