Comments on: WD’s new 2TB drive delivers on green promise

By: Wes Felter

Wes Felter — Tue, 01 Sep 2009 21:48:51 +0000

Anon, that’s what Atrato did (not that you’d know it from their site, but I digress). However, you have to consider that 2.5″ disks are more expensive per GB than 3.5″, so you have to calculate whether the power savings is large enough to compensate for the extra disk cost.

By: Anonymous

Anonymous — Fri, 28 Aug 2009 16:29:20 +0000

Ok…I need some help here.

It takes 3.7 watts to keep the “GreenPower” disk spinning (at it’s lowest speed). But it only takes 0.85w to keep WD’s Scorpio Blue 1TB laptop disk spinning. That’s less than half as much power-per-GByte for WD’s laptop SATA disk vs. desktop SATA.

When the 2TB “GreenPower” disk is in “standby” mode (completely spun down), it is still using as much power (0.8W) as the laptop disk does when spinning at full speed.

What sense does it make to invest in MAID or related technology for managing spinning-disk related power consumption when all you have to do is switch to laptop disks and achieve more-than-equivalent power savings — without having to ever spin down?

Why don’t we ever hear disk drive manufacturers talk about the fact that laptop disks use only a small fraction of the power-per-GByte of desktop disks?

By: Greg Schulz

Greg Schulz — Tue, 25 Aug 2009 23:40:20 +0000

While not widespread or commonly deployed particularly in enterprise storage arrays, as to Steves point about variable speed disk drives, you might want to check with HGST as I recall them having a drive that can change its RPM from 5400 to 4000 or so RPMs as part of an energy saving mode.
Is changing the RPM tricky, perhaps that why most are not doing it yet. However looking at disk drives and where they are saving power, sure RPM has a play actually something’s needs to keep the “flywheel spinning” once it’s up to speed (hence initial surge), however so to do turning off r/w heads or other circuitry that consumes power.
Here’s a link to some material looking at intelligent power management (IPM) and variable drive power savings, something we should be hearing more about in the not so distant future to overcome 1st generation MAID or drive spin down woes.

http://storageio.com/Reports/StorageIO_WP_Jan02_2008.pdf

Cheers gs

By: Moe S.

Moe S. — Tue, 25 Aug 2009 17:44:55 +0000

The comparisons are against 7200 rpm drives. The only thing power savings is the lower RPM. Would be interesting to compare against 5400 RPM drives as well.

By: Robin Harris

Robin Harris — Tue, 25 Aug 2009 01:22:55 +0000

Stephen, for some reason the data sheet doesn’t give the RPM either, preferring to reference “Intellipower.

OK WD’ers, what is the answer?

Robin

By: Stephen Foskett

Stephen Foskett — Tue, 25 Aug 2009 01:13:12 +0000

Although I am as enthusiastic as you about this great drive series, WD has clarified that they do not vary the spindle speed. Although a variable-speed drive would be cool, this would be a very tricky feat to manage for not much benefit. WD doesn’t say what speed the drive does spin at, but acoustic tests show that it’s just plain old 5400 rpm.

Also, note that the RE4-GP is very similar to the existing (consumer) WD20EADS, according to Tom’s Hardware.