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Hitachi Deskstar P7K500

Energy-Saving Hard Drives

Hitachi is close to releasing its next generation desktop hard drive, which is expected to replace the five-platter Deskstar 7K1000 with units using fewer moving parts. This could also bring an opportunity to update the energy-efficient product lineup, which, at this point, includes only capacities of up to 500 GB. Considering that efficiency is often measured by storage capacity per watt, this doesn’t put WD in front.

A hard drive that requires little power when it’s idle but doesn’t perform well might require more total power to complete a particular task than another product. Hence performance is also still important, because a particularly slow hard drive will counter its efficiency benefits through longer processing times at higher power consumption states.

energy efficient hdd

There are four capacity points available: 500, 400, 320 and 250 GB. The latter are mainly interesting for PVRs and similar consumer electronics devices, as most of the hard drives in the PC desktop mainstream should provide at least 500 GB of capacity. Smaller capacities won’t provide much cost savings on a new PC, but will certainly result in insufficient storage capacity for the predictable future. However, Hitachi clearly targets the consumer market, as the Deskstar P7K500 is available with SATA or UltraATA interfaces, the latter of which still dominates the consumer storage market and the low end.

The P7K500 drives all rotate at the standard spindle speed of 7,200 RPM, while Western Digital decided to reduce speed in order to reduce power requirements. All UltraATA versions have 8 MB of cache memory, while the SATA versions (with the exception of the 250 GB entry-level drive) are equipped with 16 MB cache. The drives are based on a 250 GB per platter storage density, which means that the 250 GB model runs on a single platter, while all other capacities utilize two platters.

The Deskstar P7K500 is indeed much more efficient than other 3.5” hard drives running at 7,200 RPM: it consumed 4.7W of idle power, which is slightly more than the statement we found in Hitachi’s datasheet (4.5 W). While this power requirement is clearly higher than the results we measured for the Western Digital GreenPower drives, we found that the maximum power requirement is actually amazingly low at only 6.6 W—other 7,200 RPM drives easily require between 9 and 11 W when a lot of head movement is involved. This is also consistent with the “up to 40% operational power savings” stated by Hitachi. Note that the UltraATA hard drives are generally more efficient, as the parallel interface requires approximately 250 mW less power than Serial ATA connections.

Hitachi says that it used power saving technologies that were introduced on Travelstar notebook hard drives. This could be the reason for the long average access time of 18.7 ms, which is as much time as a 2.5” hard drive would take. However, it provides a good explanation as to why Hitachi maintains such low maximum power consumption.

energy efficient hdd

energy efficient hdd

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  • 0 Hide
    jeremyrailton , June 3, 2008 7:06 PM
    according to the conclusion table, hitachi has a 5400gb drive. i want one!
  • 1 Hide
    Gudas , June 5, 2008 9:26 PM
    The Hitachi P7K500 series has a nice feature - if you activate "Low RPM idle" mode via the Feature Tool, the drive slow down from 7200rpm (to about 4500rpm) after 10 minutes when not accesing it. I have one (250GB model) and it's working great, it helps also to reduce the sound of the rotating platters. It would be nice to mention it in the review.
  • 1 Hide
    brndon1988 , June 7, 2008 7:49 PM

    they made raid compatible hard drives for faster writings, ect. if you want a 5400gb hard drive, just don't hold anything that you use regularly with something that massively slow.

    unless your a big corporation, a music/movie addict, or a porn addict. (home users, that's you) you wouldn't need it for much.
  • 0 Hide
    Anonymous , June 9, 2008 6:08 PM
    why not just use SSD? ...idk, just a thought
  • -1 Hide
    randomizer , June 10, 2008 12:53 AM
    Crap capacities?
  • 0 Hide
    Anonymous , June 17, 2008 5:31 AM

    I'm a owner of two Hitachi P7K500 500 GB hard drives, but I haven't been able to enable AHCI mode on my Gigabyte GA-P35-DS3L (rev. 2.0) motherboard. Whenever I enable the option in the BIOS (I don't remember the exact name right now), next time it boots up it just won't even detect the drives.

    If someone can help me with this issue, I'd pretty much appreciate it. Thanks in advance.
  • 0 Hide
    Anonymous , July 8, 2008 2:52 PM
    You need install drivers os SATA contoller,
  • 0 Hide
    drewmcg , August 13, 2008 1:45 PM
    The Hitachi also comes with a 16mb cache--too bad this review did not use that model, since all the other drives here use 16-32mb caches.