Im using a X850Xt and the latest ati drivers (catalyst 5.8) and when i go from smooth shade all when working in maya to high quality rendering, i get these black marks all over the surface. Its like what you see when you drag vertices through eachother.
Here's a picture...
I've found 1 or 2 of the same problems on google but they had no solution. My card isnt overheating and it was like this when i was using 5.6 drivers aswell.
Anyone have any suggestions?