Enjoy great storage in an unusually quiet environment with the Western Digital Green 2TB SATA hard drive. Computers use a lot of energy, but the WD20EZRX is designed to minimize your machine's energy use and carbon footprint. It still brings plenty of performance to the table with a hefty 64 MB cache and 7200-RPM rotational speed, but it is specially tuned for power efficiency and quietness. The biggest power draw of any hard drive is the motor that spins the platters. What the WD Green does is stop the platters and park the heads after eight seconds of non-use, relying on the large cache to cover the time needed to spin up. The result is a quieter and cooler system that sips less energy than standard desktops do.