Seagate, Western Digital go green with new 2TB drives

Capitalizing on the buzz around green IT, Seagate and Western Digital have released new "green" hard drives designed to use less power (in part by spinning more slowly than the latest generation of drives) and produce less heat (thus requiring less cooling).

The question is: Does performance suffer as a result? I tested two 2TB SATA 2 internal hard drives to find out.

How we tested

In order to test the drives, I installed them into a Dell Dimension desktop running Windows XP SP3 and connected them to Promise Technology's SATA300 TX4302 card, which enables older systems to benefit from SATA technology using a standard PCI slot.

I tested the drives with HD Tach 3.0 from Simpli Software using its grueling Long Bench test, which uses 32KB blocks for reads and writes across the entire drive. I also used version 2.55 of the HD Tune benchmark test (since it's always a good idea to try more than one benchmark when you can).

Seagate Barracuda LP

Seagate's new $US450 Barracuda LP SATA 3Gb/s 2TB drive ("LP" meaning low power) spins at 5900 rpm (most lower-power drives spin at 5400 rpm).

According to Seagate, the drive uses as much as 50% less electricity than standard desktop hard drives and up to 25% less than competitors' "green" drives. It uses 6.8 watts when in operation, which is 15% less than the 1.5TB Seagate Barracuda drive I tested in October 2008. It uses just 5.5 watts when in idle mode.

Among its other environmentally friendly properties: Seagate claims that 70% or more of the materials used in the drive are recyclable and that the drive meets the RoHS (restriction of hazardous substances) environmental standards. According to Seagate, the drive is also well suited to newer low-power PCs, networking appliances and personal attached storage devices.

Seagate uses the slogan "The new low-power drive that won't slow you down" on its data sheet. However, its performance certainly isn't as good as the current slate of full-power traditional drives; you'll pay a 10% penalty for eco-friendliness. On the HD Tach test, the drive had a burst speed of 113.8Mbit/sec. and an average read speed of 92.4Mbit/sec. Compared to my results when I tested last year's 1.5TB Barracuda, burst speed is 13.5% slower and read speed is 10% slower.

HD Tune reported an average transfer rate of 74.3Mbit/sec. (a 20% decline over last year's Barracuda), a burst rate of 77.9Mbit/sec. (16.5% slower), and an average access time of 12.2 milliseconds (an 8.9% drop).

Western Digital WD RE4-GP

Western Digital is proud of the "green" bona fides of its new enterprise Green Power drive. The company says it has reduced average drive power consumption by up to 50% over competitors' drives and about 25% over its previous generation of RE-GP drives. Like the Barracuda LP, the drive runs quiet and cool.

The $US469 WD RE4-GP (for Green Power) achieves its energy savings in part from its IntelliPower feature which, according to the company, balances spin speed, transfer rate and caching algorithms to provide power savings without crippling performance. Western Digital doesn't even list its rotational speed in RPMs -- instead, the company just shows "IntelliPower" on the spec sheet (and according to a company representative, they do not "spec RPM" for their Green Power lines of drives).

Another energy-efficiency feature, IntelliSeek, calculates the best seek speeds to keep power consumption, noise and vibration to a minimum. IntelliPark reduces power even further by unloading recording heads during idle periods to reduce aerodynamic drag and eliminate use of the read/write channel electronics. The drive's active power management invokes idle mode when possible to cut power consumption; full drive recovery from idle mode is under one second.

For the record, the drive uses 6.8 watts during read/write operations and 3.7 watts when idle. Western Digital claims that for "large, data-hungry financial institutions and Web service providers," electricity costs can be reduced by up to $US100,000 per year with this drive (at $US10 per drive per year, based on average U.S. utility rates).

In HD Tach tests, the drive had a burst speed of 107.9Mbit/sec. and an average read speed of 91.0Mbit/sec. (both results are slower than the Barracuda LP). HD Tune reported better performance than for the Barracuda LP: an average transfer rate of 86.6Mbit/sec., a burst rate of 90.0Mbit/sec., and an average access time of 11.8 milliseconds.

Summary

If "going green" is your new IT mantra, and saving money on direct power costs (and indirect savings through reduced cooling requirements) is more important than the fastest performance, these drives are noteworthy options. And for people who use desktop applications that don't read and write large graphics or document files and that remain idle for most of the time (while you make changes to a paragraph in Word, for example), going green makes sense.

The Western Digital's slightly better performance in the HD Tune tests gave it an edge in this head-to-head comparison, possibly in part to its 64MB cache (compared to the Barracuda's 32MB). On the other hand, if you prefer the HD Tach test results, the Seagate drive is the one to choose. No matter which drive you select, these "green" drives can't match the performance of their more energy-hungry siblings, but for everyday open/edit/save chores, both offer sufficiently solid performance to keep your computing tasks flowing smoothly.