3.5" WD RE4-GP 1.5 TB SATA hard drives offer data-hungry organizations massive capacity with significant power savings and lower cost of ownership compared to competitors standard enterprise-class drives. These drives are designed with WD GreenPower Technology to deliver power savings as the primary attribute and are equipped with 64 MB cache, dual processors, and IntelliPower, a fine-tuned balance of spin speed, transfer rate, and caching algorithms designed to deliver both significant power savings and solid performance.