Mobile Hard Drives 250 GB, 3 Gb/s, 16 MB Cache, 7200 RPM Designed with top-of-the-line notebook computers in mind, this high performance drive delivers the capacity and speed needed to supercharge a notebook PC without compromising battery life or quiet acoustics. Features like these also make this drive an outstanding option for compact desktops, external hard drives, gaming systems, and blade servers. Key Features Desktop-class performance for notebook computers - With 7200 RPM spin speed, 16 MB cache, and capacities up to 320 GB, these drives enable you to have the best of both worlds: the capacity and performance of a desktop PC with the convenience and portability of a notebook. Massive capacity - WD's 320 GB 2.5-inch drives offer huge capacity for space-hungry operating systems like Windows Vista™, with plenty of room left over for photos, music, and video. Low power consumption - With technologies like IntelliSeek™, which calculates optimum seek speeds to lower power consumption [View demo] and SecurePark™, which reduces power by parking the heads during low power idle mode [View demo], this drive delivers 5400 RPM-equivalent power consumption in a 7200 RPM drive. Quiet - In a notebook drive, silence is golden. WD’s exclusive WhisperDrive™ combines state-of-the-art seeking algorithms to yield one of the quietest 2.5-inch hard drives on the market. Reliable and rugged WD's ShockGuard™ technology protects the drive mechanics and platter surfaces from shocks during shipping and handling and in daily operation. WD's SecurePark parks the recording heads off the disk surface during spin up, spin down and when the drive is off. This ensures the recording head never touches the disk surface resulting in improved long term reliability due to less head wear and improved shock tolerance. Tested for compatibility - We perform tests on hundreds of systems and a multitude of platforms in our FIT Lab™ and Mobile Compatibility Lab to give WD customers confidence that our drives will work in their systems. Ideal ForPortable digital devices of all kinds, including notebook computers, external storage, and digital media players. Performance Specifications Rotational Speed 7,200 RPM (nominal) Buffer Size 16 MB Average Latency 5.50 ms (nominal) Seek Times Read Seek Time 12.0 ms Track-To-Track Seek Time 2.0 ms (average) Transfer Rates Buffer To Host (Serial ATA) 3 Gb/s (Max) Physical Specifications Formatted Capacity 250,059 MB Capacity 250 GB Interface SATA 3 Gb/s Physical Dimensions English Height 0.374 Inches Length 3.94 Inches Width 2.75 inches Weight 0.22 Pounds Metric Height 9.5 mm Length 100 mm Width 69.85 mm Weight 99 gm Environmental Specifications Acoustics Idle Mode 22 dBA (average) Seek Mode 0 25 dBA (average) Temperature (English) Operating 32° F to 140° F Non-operating -40° F to 158° F Temperature (Metric) Operating -0° C to 60° C Non-operating -40° C to 70° C Humidity Operating 8-90% RH non-condensing Non-operating 5-95% RH non-condensing Altitude (English) Operating -1,000 feet to 10,000 feet Non-operating -1,000 feet to 40,000 feet Altitude (Metric) Operating -305M to 3,050M Non-operating -305M to 12,200M Vibration Operating 0.00459 g²/Hz (10 to 500 Hz) Non-operating 0.05102 g²/Hz (10 to 500 Hz) Electrical Specifications Current Requirements 5 VDC Read/Write 500 mA Idle 400 mA Standby 50 mA Sleep 30 mA Power Dissipation Read/Write 2.50 Watts Idle 0.85 Watts Standby 0.25 Watts Sleep 0.15 Watts As used for storage capacity, one megabyte (MB) = one million bytes, one gigabyte (GB) = one billion bytes, and one terabyte (TB) = one trillion bytes. Total accessible capacity varies depending on operating environment. As used for buffer or cache, one megabyte (MB) = 1,048,576 bytes. As used for transfer rate or interface, megabyte per second (MB/s) = one million bytes per second, megabit per second (Mb/s) = one million bits per second, and gigabit per second (Gb/s) = one billion bits per second.