I have this model and 640GB. These discs are to be avoided at all costs. They have a nice look, a big connector and an apparent nice finish, but they are ABSOLUTELY NOT RELIABLE !!! Power supplies burn out one after the other, they plant my Mac because they do not know out of their day before the Iomega service pays the same warranty (20 euros for having the phone!). NOT TO BUY !!! Why should absolutely put a star to a product that does not deserve?