I have a Pentium II 400 oc'ed to 450 w/96Mb RAM, A-Trend 6240 mobo, VooDoo 3 3000 and in Descent3 and UNREAL they allways hitch because they read from the hard drive, I've done everything from changing CPU's to increasing mem and no change, PLEASE Help
My poblem was similar cause the game was always looking for data on the drive, like you enter a new room and it would stutter like it does when you read from the drive.
Make sure your disk is in DMA mode and in bios check what UDMA or PIO mode you can get the higher the better. I also for some reason had a swap file. Either let windows manage your virtual memory or make a swap fil that is max=min so windows doesn't constanly resize it. The best size is from 150 - 250.
Check your hardsisk is not ancient if it is sve your self worry and get a good one eg Western Digital they are the best quality.