After adding a 120 GB IBM (ATA) to a G4 400 Sawtooth AGP, I then replaced the tiny 10G stock Maxtor with a 120GB 8m cache western digital. BIG MISTAKE! Not only is the Western D slower than the 2 cache IBM, I've now been getting numerous crashes with photoshop and premiere. There may also be a problem exporting to tape from a western D (in an apple) to a Canon camcorder - which I haven't tried yet. So, despite $ hardship, I've bought another IBM 120GB from owc and am relegating the Western to a backup external hard drive only. Just my experience. Lynn