Colleague Dan Ragle, who compiles our weekly EIT Planet Product Guide, this week highlights an energy efficient external hard drive from Western Digital. The new My Books, which are becoming iconic in the world of external storage, now house the company's GreenPower desktop drives.

This is on top of its auto-on/off functionality that keeps the drive off until plugged into a machine and automatically powers down then the USB cable is pulled. I've used enclosures that have a switch in the back only to find out that I forgot to power it off overnight, so this feature alone scores big in my book (pun so intended).

New to the My Book line is the vendor's announcement of their GreenPower (GP) line of drives; making their company wide debut in the My Book series this month. First available in the vendor's Caviar drives (in 1 TB capacities), the GP drives boast reduced power consumption by way of three primary technologies: IntelliPower, which the vendor describes as a tuned balance of spin speed, transfer rate, and cache size; IntelliPark, which automatically unloads the heads during idle; and IntelliSeek, which calculates optimum seek speeds depending on the physical location of the target data on the disk. According to the vendor, the technologies combine to reduce power consumption per drive by 4-5 watts on average. The 1 TB Caviar GP drives debut first in the My Book offerings; with desktop Caviar GPs to follow in August. The vendor plans to introduce GP versions of their WD RE drives (drives targeted to RAID implementations) and WD AV drives later in Q3.

The 500 GB version (model number WDG1C5000) retails for $219.99, though with a little looking around, you can score one for less.