I have found that any hard drive you can plug in and power will be usable in a Mac once formatted with Disk Utility. My sister still adheres to PEE CEE. She has had disks that were unreadable on her PEE CEE for some PEE CEE reason or another. For instance she could not change operating systems or reformat because the disk had been formatted in win2000 so her PEE CEE said it was stuck forever. I took it home, plugged it in, erased it in 20 seconds (Instead of the 30 minutes hers takes when it does work), gave it back to her and she was able to use it. Pretty cool huh? I AM NOT AN EXPERT