Hi,
This issue is bugging me for quite some time - My rig is A64 3000, 1GB, 6600GT AGP, NF3 250GB. I have one 200GB WD SATA HD and a 120GB WD PATA HD. Windows XP Pro is installed on the SATA drive.
The problem is that the HDs always feel busy, even if there's not much stress in the system...