The Western Digital WD1600HLHX VelociRaptor internal hard drive is equipped with a SATA III interface with a speed of 6 Gbps, double that of standard Serial ATA drives. The Western Digital 160 GB Hard Drive boasts a rotational spindle speed of 10,000 RPM, which decreases latency when the system is reading and writing data to and from the drive. A 32 MB cache serves as onboard RAM, storing information about recently accessed data instead of sending it to the drive itself, thus increasing the access speed to frequently used files within the Western Digital 160 GB Hard Drive. The Western Digital WD1600HLHX internal hard drive features an average latency of 3 ms with a typical drive-ready time of 8 seconds. The Western Digital 160 GB Hard Drive has an operational temperature of 41 to 131 degrees F, with non-operational temperatures of -40 to 158 degrees F. This Windows/Mac compatible hard drive measures in at 1 inch high by 5.8 inches long by 4 inches wide, and weighs 1.1 lbs.