The 150 GB 3.5" Enterprise Raptor X Serial-ATA Internal Hard Drive from Western Digital is a high-capacity internal drive designed for use in servers. The drive is housed in a clear case which allows you to actually see the drive in operation. Boasting a Serial ATA interface that delivers sustained transfer rates of up to 84 MB/sec, a large 16 MB data buffer and a rotation speed of 10,000 rpm, this drive is an excellent solution for adding storage capacity to your desktop workstation or server.