Hard drive Hard drive interface: Serial ATA III Hard drive capacity: 4000 GB Hard drive size: 3.5 " Hard drive speed: Variable RPM Device type: HDD Drive device, buffer size: 64 MB Bytes per sector: 512 IntelliPower: Yes Data transfer rate: 6 Gbit/s Certification: NRCAN, RoHS . System requirements Windows operating systems supported: Windows 7 Home Basic, Windows 7 Home Basic x64, Windows 7 Home Premium, Windows 7 Home Premium x64, Windows 7 Professional, Windows 7 Professional x64, Windows 7 Starter, Windows 7 Starter x64, Windows 7 Ultimate, Windows 7 Ultimate x64, Windows 8, Window Mac operating systems supported: Mac OS X 10.6 Snow Leopard, Mac OS X 10.7 Lion, Mac OS X 10.8 Mountain Lion Weight & dimensions Width: 102 mm Height: 26 mm Depth: 147 mm Weight: 690 g . Packaging data Quantity: 1 Packaging width: 127 mm Packaging depth: 63.5 mm Packaging height: 191 mm Package weight: 810 g