The PS3 is compatible with just about any 2.5-inch SATA notebook hard disk. Both 5400-RPM and 7200-RPM drives should work fine. The physical size of the hard disk is important because it has to fit the PS3's 2.5-inch drive tray. As far as storage capacity goes, it doesn't make sense to go through the trouble of upgrading unless you go big: We're talking 120GB, 160GB, or even 250GB.