I have the same issues......My temps are fine though. I used to run LFS with my 9700pro at 80-90fps now with my X800XL my fps are 20-30fps. Everything on my PC is fine software wise and drivers. I have a program to gauge if my cpu throttles back or not and I get nothing. It goes strong
my specs:
P4 2.4b O/C @2.97Ghz
MSI 845E 533 mhz
80 gig Maxtor 7200 rpm
1024MB Corsair PC3200 Dual Channel DDR 400Mhz runing @ single channel
ATI X800XL 256DDR3 radeon