That does not sound right. Not that I have that large a HD, but my Recordings section is about 100 GB filled up pretty much all the time, and it takes nowhere near that long to make a selection. And my computer is a *lot* slower than yours. Not that this will help you in any way, but I think that you shouldn't be looking at performance boosting, you should try to figure out the root cause of your problem...
I'm not always right
Accent HT-400 Case, AMD Athlon 64 3800+ 1024MB, 1TB+300GB+180GB, WinXP Pro-SP2, NVidia 7600GT
Nova-T USB2, PVR-350 recording from Dilog 355 DVB-T box, USB-UIRT (receiving & transmitting)