Do 'Green' Hard Drives Make a Difference?

WD Caviar Green HDD photo

Photo: Western Digital
How Energy Efficient Are They Really?
The cool people at Ars Technica have a piece about 'green' hard drive. They look at the energy usage of regular models vs 'green' models to see how much energy would be saved by going that route.
WD Caviar Green HDD photo

Photo: Western Digital

The first thing to note is that 'green' hard-drives are typically slower than the regular models. That's how they save energy; by spinning their platters at a speed of 5400 RPM (or close to that) instead of the more common 7200 RPM, and by going into sleep mode more often (I have an external WD 'Green' HDD, and it seems like if you leave it alone for 10 minutes it spins down).

So if what you need is maximum performance, these problems aren't for you, though if what you need is performance but not a lot of space, going with a solid state hard drive (SSD) could give you the best of both worlds (most SSDs use only a couple watts of power - they're the future, but still expensive). So what about the HDDs that Ars looked at?

For example, a 1TB Western Digital Caviar Green model that runs at 3.0 Gb/s with a 32MB cache consumes an average of 4.8 watts when reading or writing, 2.82 watts when idle, and 0.38 watts when in standby or sleep mode. A WD Caviar Black with the same specs consumes 8.4 watts when reading or writing, 7.8 when idle, and 1 in standby or sleep. You're not exactly slashing your electric bill with a green drive, but it's something. You also drop a couple of decibels in loudness going from Black to Green. [...]

In other lines of hard drives, the savings are even more modest. An EcoGreen 5400 RPM Samsung hard drive, the HD103SI, has power consumption figures of 5.6/4.4/1 watts, while an equivalent 7200 RPM drive, the HD103SJ, runs at 7.2/6.3/1 watts. Seagate Barracuda launched a line of 5900 RPM "Green" drives that still get decent savings over another of the same brand--the green version uses 5.4 watts during read/write and 4.8 when idle to a similarly specced Barracuda XT's 9.23 during read/write and 6.39 when idle. (source)

No bad, especially for the WD drive. But note that this is a relatively small portion of a computer's power consumption. If you don't need maximum performance, there's no reason not to go with a 'green' drive, but you'll make an even bigger difference by going laptop instead of desktop, or by having a smaller screen (LCD with LEDs, preferably) or a lower power CPU.

And of course, make sure to always turn the computer off or put it in sleep mode when you won't be using it for a while...

Via Ars Technica
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