I know this subject was beat to death a few weeks ago. The problem is I trashed the postings and question my memory about what I read. I may be able to get 200GB, 7200 RPM, 8MB cache ATA/100 drive to replace the aging 30GB drive that came with this G4-450 AGP machine running 10.3.3 with an ATA-4 Bus. As I recall the postings the new (to me) 200GB drive should work okay but will only show up as a 120GB drive. What iis the downside to installing a 200GB drive on Mac that will only recognize 120 GB. aRKay