XP and poor HD/Video performance

[RazB]

A relative recently bought a monster machine from Cyberpower...Shuttle 266A board,1.67 amd, 80 gig maxtor 7200, AIW 8500, 512 DDR etc. I did a performace test at PC pitstop and her supposedly (we verified it's a 7200) fast HD rated VERY slow for uncached speed 2.5 MPS, roughly half the expected speed. DMA is checked and ultra 5 is listed. ALSO, her 8500 is pathetically slow and drops frames in simple 3D games like star wars battle of Naboor(?). She's running XP home edition and I was afraid there are still issues with some hardware...ANY clues?