back to article WD's Purple reign continues: 12TB helium disks for vid spy tech

Video surveillance is an insatiable monster, constantly needing more digital storage – and Western Digital is now feeding it 12TB drives. WD's Purple hard disk family this week had a 20 per cent jump in capacity, from 10TB to 12TB, courtesy of incrementing the platter count by one to eight, and an increase in per-platter …

  1. The Dogs Meevonks

    I'm running an 8TB one of these in my mediaserver, to serve up video to devices around the house and it can easily hit transfer rates of 200mb/s across SATAIII... Which is handy when streaming to more than once device at a time.

  2. adnim Silver badge

    Shame that

    they only made them for vid spy tech.

    "Eight platters serving up 1.5TB each for data-belching surveillance cameras"

    Can they not be used for kitten pictures?

  3. DerGoat
    Angel

    Is my math dodgy?

    1.5 million hours MTBF?

    1,500,000 / 24 hours = 62500 days

    62500 / 365 = 171 years? Is this correct? Even without sleep mode, my NAS should last my whole life.

    Or until I fill up 12 TB. Doh! I'm already out of space.

    1. diodesign (Written by Reg staff) Silver badge

      Re: Is my math dodgy?

      MTBF = *mean* time between failure, not minimum or maximum.

      Your drive might last 171 years, or 200, or 300, but spare a thought for those that last 3 months or 6 months.

      C.

      1. Potemkine! Silver badge

        Re: Is my math dodgy?

        spare a thought for those that last 3 months or 6 months.

        I would rather spare a thought for those that last 1 day more than the warranty duration :doh:

      2. Alan Brown Silver badge

        Re: Is my math dodgy?

        "Your drive might last 171 years, or 200, or 300, but spare a thought for those that last 3 months or 6 months"

        I wonder how they square that kind of claimed MTBF with an actual failure rate exceeding 100% over 5 years (some drives were replaced twice or more) for a fleet of a few thousand units.

  4. Potemkine! Silver badge

    Helium

    Could someone explain why Helium is used please?

    1. Snapper

      Re: Helium

      Less resistance than air, so the drive does not have to work so hard.

      And it can say so in a squeaky voice.....

      1. MonkeyBob

        Re: Helium

        Helium is less dense than air so the heads can be closer to the platter allowing greater data density.

      2. Potemkine! Silver badge

        Re: Helium

        Thanks for the explanation!

        I guess using vacuum could be an alternative, but more expensive...

        1. Tomislav

          Re: Helium

          Unfortunately using vacuum is not an alternative because that would require a much stronger (read: thicker) casing, which in turn would reduce the available space for platters. Remember, you are limited by the 3.5" HDD case size. Filling the interior with helium helps keep the pressure difference to a minimum.

        2. Anonymous Coward
          Anonymous Coward

          Re: Helium

          No it wouldn't.

          The drive heads still 'fly' on a cushion of air/gas. In a vacuum the heads would drag along the surface of the drive.

          Helium allows the head to fly closer to the disk, and as magnetism works this allows a much stronger field to record to the disk and/or using less power, it also mean the heads can be flung around much faster and/or with less power inpout to move them.

  5. Paul Slater

    Isn't there some sort of worldwide shortage of helium?

    1. SGWilko

      Nope, that'd be CO2 - yup, we are short on CO2.

      Kinda makes you wonder what all this greenhouse gas/global warming fuss is about, eh?

    2. Z80
      Boffin

      Boffins from Durham and Oxford found an estimated 54 billion cubic feet (610968 Olympic-sized swimming pools) of helium under Tanzania a couple of years ago. That has eased the supply worries somewhat.

      1. Alan Brown Silver badge

        " 54 billion cubic feet ... of helium under Tanzania "

        Which immediately leaked away through the hole drilled to find it.....

        More seriously: There's helium in every natural gas field but it generally costs more to recover it than you get from selling it so drillers normally just vent it. The US broke the economics of helium a few years back by dumping their strategic reserve on the open market and crashing the price.

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