WD10EACS-00D6B0 Western Digital Caviar Green 1TB 7200RPM SATA 3GB/s 16MB Cache 3.5-inch Hard Drive

As hard drive capacities increase, the power required to run those drives increases as well. WD Caviar GP makes it possible for energy-conscious customers to build systems with higher capacities and the right balance of system performance, reliability, and energy conservation. The performance of this 5,400 rpm disk drive is very close to that of the current 7,200 rpm disks. The main reason for this is the increased area density that the drive uses. This allows more data to pass under the heads and thus increases throughput. So you get the reduced power requirements of a slower spindle speed coupled with high performance.