Originally Posted by nitd_kim
you might just be hitting a bottleneck with your cpu. Also, 5770s arent really that beefy of a card. Maybe you have supersamplingAA turned on?
5770's have a fair amount of power considering they are mid grade cards.
I have heard that having higher setting on should (in theory) put more stress on the video cards and create a more even balance of power. With the video cards working hard they won't be chewing through the game as fast and catching up on the proc.
Now I have no proof for this so I may just be blow hot air. Sorry if I'm wrong and will stand corrected if someone has proof that is isn't true.
But I agree that I think it is driver/setting based versus a hardware issue.