Western Digital has announced new hard drives using up to 40 percent less power than competing drives.

These are serial ATA (SATA) drives in a new GreenPower-branded line, with 500GB, 750GB and 1TB capacities. They use on average 4 to 5 watts less than similar-size and format drives from Hitachi GST, Fujitsu, Seagate and other suppliers.

Four technologies provide the new drives' power efficiency:

- IntelliPower balances spin speed, transfer rate, and caching algorithms to avoid always spinning at top speed. Also less current is used during start up allowing more drives to spin up simultaneously resulting in faster system readiness.

- IntelliSeek optimises seek speeds to lower power consumption, noise and vibration.

- IntelliPark automatically unloads the recording heads during idle to reduce aerodynamic drag and disables read/write channel electronics.

- Active Power Management monitors a drive's workload and automatically invokes idle mode whenever possible to reduce unnecessary power consumption. Drive recovery time from idle mode is less than one second.

Western Digital believes that large datacentres could save up to $100,000 annually if they used 10,000 of these new drives rather than ones from other suppliers. At a PC level users might save $10 (about £5 at standard conversion rates) a year per drive.

Tom McDorman, VP and GM of the company's enterprise business unit, said: "WD's RE2-GP enterprise line of hard drives allows customers to expand their storage needs, reduce their total cost of ownership, and improve the environment all at the same time."

Datacentre suppliers already selling more power-efficient products were quick to endorse Western Digital's new line.

Tony Gaughan, Rackable Systems' chief products officer, said: "Western Digital's new RE2-GP hard drives are an excellent choice for customers deploying Rackable Systems' newest generation of Eco-Logical storage systems - enabling even greater efficiency and performance."

David Driggers, Verari Systems' CTO, said: "By utilising WD's latest GreenPower technology, Verari is able to provide enterprise customers with a solution that delivers one of the most energy-efficient systems available today."

The new drives are available from Western Digital's online store with MSRPs of $149.99, $249.99 and $349.99 for the 500GB, 750GB and 1TB drives, respectively.