I've been thinking about disk upgrading, too, and I have a basic question...

My motherboard has, according to the specs on the ASUS website:

South Bridge:
2 x UltraDMA 100
2 x Serial ATA
Promise 20378 RAID controller (optional):
1 x UltraDMA 133 support two hard drives
2 x Serial ATA
RAID 0, RAID 1, RAID 0+1, Multiple RAID

My question is pretty simple... Which is the faster and/or more reliable interface? Serial ATA or Ultra DMA? When I get a new hard drive, should I consider going SATA with it? Right now I'm doing the UDMA with an 80-conductor ribbon cable. I think those tiny little SATA cables are pretty neat and I'm itching to use them.