How much "rest" does an external HD need?

Discussion in 'Mac Basics and Help' started by GanChan, Jul 4, 2005.

  1. GanChan macrumors 6502a

    Jun 21, 2005
    I have a new Western Digital 80G external drive (39 bucks after rebate from CC, couldn't resist), and I'm wondering how anal I should be about powering it down at the end of each day or work session, like I do with my primary hard drive. The reason I ask is, after I un-mount the drive from my desktop, the drive stays on; pushing the Power button makes the button blink a few times, but it doesn't actually power off until I detach the AC cable.

  2. aussie_geek macrumors 65816


    Apr 19, 2004
    Sydney Australia
    Drive manufacturers publish various specs on their drives. One is 'Start Stop Cycles'. This is the number of times the disk can be started up from zero RPM to operating RPM. A typical drive has an expected minimum of 50,000 start stop cycles.

    So, theoretically the more times you stop / start your drive, you are wearing it out.

    But then on the other hand, maybe the disk motors / bearings will wear out sooner on a drive that is rotating constantly. One or the other will happen over time.

    But we are talking years worth of HD activity for these drive failure symptoms to develop. The way I see it, it's totally up to you - there are no pro's or cons regarding leaving a disk on.

    The most damage to a disk is done during a read / write and the power goes out. The drive heads can hit the platter and eat it!!

    More to read here

  3. jalagl macrumors 6502a


    Jun 5, 2003
    Costa Rica
    Mine is ON all the time I have my laptop at my desk, including at night.
    Has been like that for over a year now, with no significant sign of problems.

    Hope it stays that way for a while...
  4. Jigglelicious macrumors 6502


    Apr 25, 2004
    Allowing a hard drive to spin constantly is better for it than constantly shutting it off and turning it on, which wears it out quickly. This is one of the primary reasons why the "Put hard disk to sleep" feature in OS X can actually be more harmful than helpful, and its one of the first things I turn off on a fresh copy of OS X.
  5. wdlove macrumors P6


    Oct 20, 2002
    I leave my external Mercury OWC Elite HD on all the time. Except to turn it off when doing a major upgrade like 10.3.9. I have been doing this for over two years now, no problems. So I guess that I will see in another year or two how this works out.
  6. Scarpad macrumors 68000


    Jan 13, 2005

    I have that same drive are'nt you concerned about heat? It's a fanless case, sure it's aluminum but then it's encased in ventless plastic and it dows get warm/hot. I'm going to start leaving mine on but then have it go to sleep when not in use, otherwise I think Heat will kill it first. I might seek a fan alternative

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