Western Digital's RE4-GP (WD2002FYPS) internal hard drive offers most of the energy-saving features of the company's Caviar Green line of consumer drives, but it also includes server-friendly features such as reduced vibration and noise.
Although more expensive than a Caviar Green drive, the RE4-GP's lower power consumption and improved performance make it worth the extra outlay.
The Western Digital RE4-GP has a 2TB capacity spread over four platters. It also uses 64MB of cache instead of the 32MB you would find on the 2TB Caviar Green. Western Digital claims that the drive has a mean time between failure (MTBF) of 1.2 million hours - comparable to Intel's enterprise X25-E solid-state drives.
We conducted benchmark tests with a testbed PC running a Western Digital 300GB VelociRaptor internal hard drive. In our large file test, comprising 20GB worth of 3-4GB files, the Western Digital RE4-GP internal hard drive wrote at 78.86 megabytes per second (MBps), read at 79.5MBps and performed a simultaneous read/write operation at 36.1MBps. Copying 3GB of 1MB files, the hard drive wrote at 50MBps, read at 66.7MBps and performed a simultaneous read/write operation at 38.5MBps. While the Western Digital RE4-GP isn't as fast as the Velociraptor it is still significantly better than the 2TB WD Caviar Green (WD20EADS).
The Western Digital RE4-GP uses Western Digital's "GreenPower" collection of technologies - IntelliPower, IntelliSeek and IntelliPark - to cut down on the hard drive's power consumption. IntelliPower varies the drive's spin speed to reduce power consumption when spinning up the drive and during normal operation; as a result, Western Digital doesn't provide a fixed spin speed for the drive.
The other two technologies - IntelliSeek and IntelliPower - affect the heads that the drive uses to write and read from the platters. IntelliSeek calculates the optimum seek speed while IntelliPark moves the drive's recording heads to a secure position when idle. According to WD, these technologies help save energy and reduce noise and vibration.
During our tests, the Western Digital RE4-GP drive consumed 6.8 Watts when writing, 6.1W when reading, and 7.1W when performing a simultaneous read/write operation. It consumed 4.5W when idle. This is more than the 3.7W quoted by Western Digital and is probably caused by the variable spin speed. Overall, the RE4-GP consumed less power than the enterprise-focussed 1TB RE2 GreenPower drive.
Noise was minimal even during intense operations; we were unable to detect vibration without feeling the underside of the drive. The Western Digital RE4-GP drive uses Western Digital's Rotary Acceleration Feed Forward (RAFF) technology, which the company says reduces vibration caused by other hard drives close by.
The Western Digital RE4-GP internal hard drive maintained a temperature range of 33-39 degrees Celsius during testing in an open-air environment, which is slightly higher than the temperatures the 2TB Caviar Green (WD20EADS) registered.
Overall, the Western Digital RE4-GP internal hard drive offers a great compromise between performance and low power consumption. Western Digital's energy saving and vibration reduction technologies, combined with a higher cache than WD's 2TB Caviar Green drive and fast throughput speeds, make this drive a great addition to data centres.