I have tried running UT3 on both my XP SP3 and Vista Ultimate x64 SP1 O/S's and have the same problem with both. The game runs EXTREMELY slow on both to the point where it is unplayable. It will run smoothly for a few seconds then the video will totally freeze for a few seconds, over and over. I would think that my hardware is very fast but something is not right. I have the latest video drivers. I have tried shutting down every program and even every unnecessary system service I could as well as changing 3D settings in the Nvidia Driver Control Panel to raise performance. I have also tried reinstalling DirectX 9.0c without luck. My system specs are below. Any ideas?
AMD Athlon X2 6400+
Asus M3A78-EMH HDMI mobo
XPX Geforce 8600GTS 256MB XXX Edition
8 Gig RAM
AMD Athlon X2 6400+
Asus M3A78-EMH HDMI mobo
XPX Geforce 8600GTS 256MB XXX Edition
8 Gig RAM