Not 100% compatible with Apple. The disk is not a normal plate but has irgdendwas plan, which is not formatted, a fixed small hidden partition. This makes on the Mac under Lion 10.7.4 trouble. The Disk Utility reports an error and the disk is not stable. Why can make a record and not try draufzuschummeln any indelible Softwarekram because the manufacturer is not easy. (I do not know what should be the backup for PCs?) - If one switches on the encryption of partitions on the Mac, there is real trouble with it.