To get that power consumption down, Green drives use a number of incremental tweaks. To start with, the spindle speed is optimised on Green drives. A number of caching algorithms manage the way data is handled to ensure that the slower spindle speed doesn't impact on performance too much. Further algorithms optimise seek operations to try and ensure the read/write heads move only as fast as they need to, which reduces power consumption and vibration.
The other major addition is a low-power spin-up, which reduces peak power requirements when the drive is starting up. This means you can equip you computer with a lower power PSU, which in itself can further save power. All told WD claims these tweaks account for a 40 per cent reduction in power consumption compared to standard desktop drives.
As well as its power saving features, WD has also used a new retention mechanism for the motor on this 2TB version. The main spindle is now fixed at both ends, which provides a more stable platform for the platters, further reducing vibrations and the resultant heat and noise.
Of course, looking at the drive, you'd be hard pushed to tell this is any different from any other hard drive, apart from the name. As with all current desktop hard drives, it comes in a 3.5in form factor with connections for SATA power and data. It uses the new SATA-II interface standard, with its theoretical transfer rate of 3Gb/s, but it's compatible with the older 1.5Gb/s SATA standard as well.
Four platters are used to create the total storage of 2TBs. This equates to a record breaking data density of 500GB per platter, which WD was keen to point out would have performance as well as power saving benefits over five platter versions. While this is partially true, we found performance can vary depending on the sort of data you're dealing with as evidenced when we compared the Seagate and Hitachi 1TB drives. Of course, the easy way to find out is to do some testing…
We ran this disk through our usual set of hard drive benchmarks. To start, we leave the drive unformatted and add it as a spare drive to our test rig. We then run the hard drive testing utility HDTune. This performs a thorough test of the drive's performance right across the expanse of its 500GB platters. At the end it spews out an accurate access time figure as well as average, maximum, and minimum transfer rates. Both read and write tests are done so by the end of this test we have a pretty clear indication of how well this drive performs.
Following this we install an identical image of Windows onto the drive(s). We then test the boot, restart, and shut down times of the system. Following this we run the HDD portion of the PCMark Vantage test suite. This runs a whole host of simulated hard drive tests including Windows Vista booting, video editing using Windows Movie Maker, and importing music into Windows Media Player. At the end it returns an overall score but also breaks down the results into individual scores.