I've got a 5400 rpm drive and a 7200 rpm drive. I recently ran some benchmarks, and the 5400 drive (maxtor 27 gb ata/66) gets only 2500 kb/s for reading and writing, while the 7200 rpm drive (seagate 80 gb barracuda) gets 40,000 kb/s reading and 16 kb/s. I know at 5400 rpm it should be slower, but this seems a little too slow. When I boot up my computer reports the drive is in LBA/ATA-66 mode, but in Windows XP the device manager says the Primary IDE Master is using PIO Mode (doesn't say what number), even though I have it set on "Use DMA if available." Is there anything I can do to speed up my drive?
Your problem is DMA related. You should find some way to enable the UDMA mode in Windows. Try removing your HD controllers in the device manager and rebooting (Check BIOS first to see if UDMA mode is enabled for all channels). Check if you can now set to UDMA mode (or if it's automatically enabled). Also if yours is a new (especially non-Intel chipset) mainboard, install the appropriate drivers first (like the VIA 4in1s).