No (notable) performance increase at all. I think I'll eventually get around to tweaking the settings to get some playable FPS but for now I cbf to do that. Runs anywhere from 10~20 fps.
Dual core Opteron 185 @ 3.0GHz
3(4) gb of DDR PC3200
Radeon 4870 1GB
@ignarukih - get fraps or some other program that has an FPS overlay. You'll notice the FPS during that screen is in the range of 2000 fps, that's why