For some reason this drive has got slower and slower with time. It is connected to an imac with OS X and it now takes 16 hours to back up my computer data. I registered the drive with LaCie, got online help but after lots of questions and answers they agreed to repair it (at a cost of £8 non returnable postage to me). I've got the unit back with a new hard drive fitted (but minus its original box) and it is even slower. Not good enough. I have demanded a full refund. I can not trust this drive.