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

Conclusion

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.

  • 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.
    Reply
  • evongugg
    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.
    Reply
  • 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.
    Sad...
    Reply
  • awaken688
    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.
    Reply
  • cknobman
    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.
    Reply
  • chunkymonster
    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?
    Reply
  • davidhbrown
    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.
    Reply
  • 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?
    Reply
  • farrellj
    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.
    Reply
  • farrellj
    Just found out...the Synology DS409+ does use Linux!
    Reply