This drive is such a joke. After reading everyone else's reviews I wonder if they even tested the design before selling it. Incredibly slow, and very flaky connection to a Mac running 10.4.9. I bought two of these, had to return one under warranty, and now wish I would have just gotten my money back for both. Don't buy it - you WILL be sorry. I got a WD MyBook Pro Edition III (1TB) and it works great.EDIT - a few months after this review I decided to take the case apart and use the drives elsewhere. Same problem - I installed the drives that were inside into two separate OS X machines, and both were extremely slow - lucky to get a couple MB/sec write. So even if you're looking at one of these just for a couple 500GB drives, stay away.