I don't exactly know when, but at some point Diablo 3 took a major performance hit. I'm running a Mac Pro with dual quad core xeons (2.26), 16 gb RAM and a Radeon 6870 and yet when running in Windows I can't seem to eek more than 35 fps out of the game anymore. The odd thing is that when running in Mac OS I get 80+ FPS and other games in bootcamp work without problem - it seems to be an issue specific to D3.

Has anyone else running 6870s come across this problem and are there any known solutions? I searched around a bit but didn't find anything of particular use...