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Picking A Hard Drive For Your NAS: New Green Beats Old Speed

When buying a BYOD NAS device or upgrading an existing NAS server with newer drives, users have to choose which hard drives are the best for their purposes. Indeed, buyers have a vast selection of choices where capacity is concerned, with modern drives ranging from 160GB to two terabytes per drive. However, with energy costs continually rising, it makes sense to keep a drive’s efficiency in mind, especially for NAS devices that house several drives.

Data Throughput is Limited by the RAID Engine

Our comparison showed that the difference in write performance between faster and slower spinning hard drives is minimal to nonexistent when they are used in a NAS. Instead, the NAS’ RAID engine becomes the limiting factor. Even when reading, drives with a spindle speed of 7,200 RPM aren’t necessarily faster. Indeed, our test bed achieved better read performance when it was equipped with the slower-spinning eco drives, since Samsung’s newer HD103SI achieves a better average data transfer rate than the HD321KJ to which we compared it.

Lower Power Consumption and Less Heat

Higher read rates aren’t the only advantage to an energy efficient upgrade, though. The system’s overall power consumption also drops because 5,400 RPM drives draw less power than their 7,200 RPM siblings. A welcome side effect of this is that the eco drives also produce less heat, meaning your NAS can run cooler and, since its fans can operate more slowly, and quieter to boot.

Check for Compatibility

Despite all of their advantages, there is one caveat when it comes to using energy-efficient drives in a NAS. Before you buy the drives of your choice, make sure to check your NAS’ hard drive compatibility list. After all, not all disks, regardless of spindle speed, may be compatible with your device. Some of the drive’s features may not be supported. If, for example, HDD Sleep Mode is ignored, the drives never spin down and the power consumption advantage of the eco models would go to waste.

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  • 5 Hide
    Anonymous , November 6, 2009 6:43 AM
    Is it a good comparison between 320 GB drives and 1 TB ones? Of course de 1 TB will perform better: much higher data density means less movement of heads and platters for the same amount of data. Gotta be faster. Nothing to do with the enclosure.

    Also I would like to mention from my own experience that heat can be a problem. I have a D-Link DNS323 and it cannot handle two server edition WD drives - it overheats.

    - Bertus.
  • -2 Hide
    evongugg , November 6, 2009 10:15 AM
    If you buy a NAS, it's better to use the recommended drives, which have been put through hard tests.
    Other drives may experience RAID problems, burnout problems, etc.
    If you want to salvage a NAS hard drive, you may be dealing with a Linux type partition.
  • 5 Hide
    Anonymous , November 6, 2009 11:14 AM
    Weird concept to compare an "old" performance drive with a new eco drive, where by default the new eco drive is outperforming the old performance drive in all categories.
    What is the expected result? Yes, we guessed right, the new eco drive is outperforming the old performance drive in a NAS environment.
    Unfortunately that comparison does not allow any conclusion whether a NAS needs a performance drive or not, it only tells us that a new eco drive is better than an old performance drive.
  • 2 Hide
    awaken688 , November 6, 2009 12:08 PM
    Totally agree with "theaxe" on this one. Not sure what this proved other than if you choice is an old performance drive vs. a new green one, choose the green one. Show me the WD 1TB Caviar Black vs. an equivalent "green" 1TB drive and then we can see more of a comparison that means something.
  • -2 Hide
    cknobman , November 6, 2009 12:23 PM
    good thing we have the comments section so I dont wast my time reading a pointless article. first thought is "why in the f would you compare a 320gb to a 1gb?" reading the comments let me know my thought is right and not to waste time reading a pointless article.
  • 0 Hide
    chunkymonster , November 6, 2009 12:35 PM
    Our comparison showed that the difference in write performance between faster and slower spinning hard drives is minimal to nonexistent when they are used in a NAS. Instead, the NAS’ RAID engine becomes the limiting factor.
    Ok, I can understand the RAID engine being the limiting factor when using off the shelf NAS solutions, especially considering most off the shelf NAS solutions use software RAID. But, would a 5400RPM drive become the limiting factor, compared to a 7200RPM, when using a hardware RAID solution like an Areca, 3Ware, or HighPoint controller card? Any guesses?
  • 1 Hide
    davidhbrown , November 6, 2009 12:47 PM
    I've been reflexively buying 7200RPM drives for everything (notebooks, NAS, desktops) for so long now, that just the *concept* of the article is a useful reminder that in some settings, other issues might be important. Too bad the specific comparison may be flawed, but it's not like exactly that hardware is going to be relevant in six months anyway.
  • 0 Hide
    Anonymous , November 6, 2009 12:51 PM
    Even with a 10 watt difference, the electricity savings is negligible. At the nation average of 12 cents per kWh, using 10 less watts 24/7 for a year works out to be a whole $10.50. On the year. Less than $1 a month. A far cry from what the article stated: "the difference jumps into the two-figure range. And that can definitely make a difference when the time comes to pay your electric bill" I'll take that 88 cents I save a month and go buy...wait, what can you get for 88 cents these days?
  • 0 Hide
    farrellj , November 6, 2009 12:54 PM
    Just one thing...many consumer NAS boxes run a cut-down form of Linux...and Samba! And that makes it much more stable than some proprietary software that hasn't been as extensively tested as Linux/Samba has.
  • 0 Hide
    farrellj , November 6, 2009 1:02 PM
    Just found out...the Synology DS409+ does use Linux!
  • 0 Hide
    icepick314 , November 6, 2009 1:20 PM
    i read somewhere that you should use green drives specifically made for RAID since it has option to change time-out period...

    otherwise NAS would think the drive is dead and give error if the drive went to sleep...

    is this wrong?
  • 0 Hide
    hixbot , November 6, 2009 3:48 PM
    icepick314 that's kinda wrong. You want TLER for raid mirror arrays because yes the raid controller might thing the drive is dead and start rebuilding. If you use a mirror array in a NAS, then yes, you want TLER. but NAS aren't always configured with a mirror array, or use RAID at all (though they often do).

    the WD greens are not recommended for linux, which is used in most NAS. the greens still have a head parking issue, they have masked that issue with the latest firmwares, but not corrected it.

    There are still no decent eco drives for NAS in the 2tb space.
  • 0 Hide
    Anonymous , November 6, 2009 4:34 PM
    I read that Synology's devices don't sleep. Is there a competing NAS that does sleep (and comes back via wake-on-lan)? That would save much more power than drive choice could.
  • 0 Hide
    Computer_Lots , November 6, 2009 5:30 PM
    I could have sworn I read an article right here at Toms that showed 1TB green drives outperforming this exact Samsung T166. I believe that the point was the higher density plus the more efficient design made the newer 5400 rpm drives perform faster than older 7200 rpm.

    Really, You don't have a 7200 RPM 1TB drive laying around to test?
  • -3 Hide
    scooter69 , November 6, 2009 6:39 PM
    Is some one trying to tell us to use "green ECO drives"? Save a blade of grass or something.Sorry had to get it out. I agree with theaxe and cknobman on this one. You can't really compaire the two. Also with the ECO "green drives", I've heard that they don't always spin-up fast enough and fall out of the RAID setup and causing it to crash at times. Am I right, or wrong?
  • 0 Hide
    False_Dmitry_II , November 7, 2009 1:54 AM
    I have a problem with the whole preface of the article. Is it kinda annyoing to do it yourself? Sure, but these kinds of devices cost over $100, and that is too much for someone like me.

    The majority of these features that are mentioned (with the notable exception of print serving, which can be added) can be had by installing FreeNAS. I took an ancient comp, slapped a SATA PCI card in it, and had it running in 10 minutes doing everything. Including serving my xbox 360 with music!

    I then proceeded to install linux instead so I could do crazier things like make the scanner accessible on any computer and of course printing too. It seems to be doing a pretty admirable job for what it is.
  • 0 Hide
    scooter69 , November 7, 2009 2:57 AM
    THANKS False_Dmitry_II, I've been thinking about using my one year old gutted maching for a over-sized NAS. My work doesn't like it much when I hyjack software and key codes. Now I have a reason to keep my older machine.
  • 0 Hide
    midnightgun , November 7, 2009 6:49 AM
    farrelljJust found out...the Synology DS409+ does use Linux!

    Far as I know, all Synology products use the same version of operation system. A scaled down, specialized version of Linux. I've had a 407e for about a year and it has worked flawlessly and is so easy to manage.

    For those that don't want to spend the money on a cage, and have an old machine kicking around there is always the Freenas option ( which I hear works well.

    As for this review... Mixing old and new drives in a comparision not designed to see the difference in old and new drives seems... Well pointless.
  • 0 Hide
    chunkymonster , November 7, 2009 12:34 PM
    Someone got down vote happy and gave a large number of posts a -1, interesting...
  • 0 Hide
    Anonymous , November 7, 2009 12:34 PM
    Opening paragraph from your article from April:
    "If you're in the market for a storage upgrade, you have some important decisions to make. First off, there's the choice to build your own solution or buy one from an established vendor. If you choose the former path, know that there are tons of options, which we'll explore in a future story. Here, we'll be going down the latter path."
    How far into the future are we talking? Obviously longer than six months. That would be an article I'd like to read.
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