Disproving a Friend's Myth

Discussion in 'MacBook Pro' started by Rhyno37, Aug 17, 2011.

  1. Rhyno37 macrumors regular

    Jul 23, 2011
    After getting my MBP, I remember something my friend once said. He has a 2010 15" MBP, and he is super anal about anyone using it, let alone himself.

    The thing he is most anal about is carrying the laptop around. He says you need to close the screen and wait for the light to stop blinking before you move it. He freaks out and says that you'll scratch the HDD if you don't.

    Now maybe I'm just ignorant on this subject, but from all the PC Laptops I had I was always carrying them around and I never messed up them.

    So is he full of bologna or in the right?
  2. MBP13 macrumors 6502


    Mar 13, 2011
    You need to tell your friend that there is nothing to worry about while carrying a Mac around before the light stops blinking or whatever ignorance he's saying. You could still type on the Mac while walking around, etc. and there will be no damage done.

    Show him this link: http://support.apple.com/kb/HT1935

    The sudden motion sensor kicks in when any sort of movement is felt, protecting the hard drive from damage. There is nothing to be afraid of.
  3. Porcelina macrumors newbie


    Oct 26, 2004
    Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_3_3 like Mac OS X; sv-se) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8J2 Safari/6533.18.5)

    But if you hit the computer yourself, the motion sensor wont protect it. Then its more safe if it has gone to sleep.
  4. gr8tfly, Aug 17, 2011
    Last edited: Aug 18, 2011

    gr8tfly macrumors 603


    Oct 29, 2006
    ~119W 34N
    When you put a Mac portable to sleep, it takes a few seconds to write out the current state of data in RAM in case of complete loss of power. Once this is complete, the drive will spin down, and the sleep indicator will start pulsing.

    HDs are designed to take a certain amount of G loading while operating. Given a choice, it's better not to move a spinning drive. There is also built-in protection which will park the head if there's too sudden a movement (the sudden motion sensor).

    In reality, as long as you don't subject it to too sudden a motion, it should be fine. I've used notebooks in moving cars with no ill effects - as, I'm sure, many others have.

    I'm pretty anal about such things myself: if I'm not in any particular hurry, I'll wait until the Mac is snoozing before moving it. Otherwise, I just move it slowly and gently into its bag. Then I wait until it's asleep - before yanking the bag up and into my shoulder.
  5. unixperience macrumors regular

    Jul 21, 2010
    yeah, it won't make a difference.

    Additionally, you could disable the hibernate/sleep thing, the light stays on solid while the ram contents are being written to the disk. if your power somehow fails while your computer is asleep, the next time you turn it on, it will load from the sleep file it made, so its basically populating the ram from your harddrive (using the info it saved before it shut off... hope that made sense)

    You can actually just enable regular sleep (doesn't create sleep file unless battery is really low like 2 or 3% ) using the terminal. This will cause your computer to immediately sleep when you close it, and the light will start blinking, not stay solid. the only disadvantage is if somehow the battery suddenly died... (with built in batteries... this isn't even really a possibility unless your battery completely instantaneously fails) you wouldn't be able to resume where you left off the next time you turn on the comp.

    anyway the command if you want to try is
    sudo pmset hibernatemode 0
    when you use a sudo command it will ask you for a password, so enter it and press enter. you can check your current status by typing in pmset -g

    if you want to return it to the original setting type
    sudo pmset hibernatemode 3
    if you DO NOT use secure memory (under privacy tab in system preferences)
    If you use secure memory type
    sudo pmset hibernatemode 7

    for more info read this http://www.macworld.com/article/53471/2006/10/sleepmode.html


    just a little more info on sudden motion sensor

    if you replaced your hdd with an aftermarket one, there is some chance that the HDD itself has a built-in motion sensor, so then you'd be doubly protected, one from apple and one from your harddrive
  6. marc11 macrumors 68000

    Mar 30, 2011
    NY USA
    You are both right. It PROBABLY wont hurt anything to move it while it is writing the sleep file, but it is also a GOOD idea to let it finish writing the sleep file before moving it. Yes the SMS will protect the HDD during a sudden DROP, but there is always always ALWAYS a chance the SMS will fail, the movement isn't detected by the SMS, etc and damage to the drive can happen. For me, I wait the few seconds for the sleep to be indicated before moving it. Unless I am physically on fire, there is no place I need to be that 5 seconds will make a critical difference and if it did, putting my laptop to sleep and my HDD would be the least of my worries at the moment.

    Damn, everyone in life seems to be in a hurry these days!
  7. Mal macrumors 603


    Jan 6, 2002
    Actually, one bad thing that has been reported (not sure if it's been fixed or not) is that if you trigger the SMS while the computer is in that state before it actually goes to sleep, the computer can wake back up even while the lid is shut. If that happens, and the computer is inside of a bag, then the temperatures could build up significantly higher than intended, which could cause damage. Granted, the machine would shut down if the processor got too hot, but other areas are designed for better ventilation and there's been reports of problems resulting from that.

    I always let my computer fully go to sleep before moving it. I can afford the 5-10 seconds, but I can't afford having my computer fail, so I'm not taking any chances with it.

  8. dsio macrumors regular

    Jun 19, 2011
    TBH, people have been moving laptops well before SMS existed, and frankly how many people do you know that have laptops with damaged hard disks caused by heads touching?

    Your friend is paranoid, hard drives are far less fragile than people think.
  9. edk99 macrumors 6502a

    May 27, 2009
    If he is that anal tell him to get rid of the mechanical HDD and install a SSD..
  10. MrJolly macrumors member


    Aug 15, 2011
    I live next door, England
    I refer the Rt Honourable Gentlemen to the following Notice in the manual. Page 16.

    Wait a few seconds until the sleep indicator light starts pulsing (indicating
    that the computer is in sleep and the hard disk has stopped spinning) before moving
    your MacBook Pro. Moving your computer while the disk is spinning can damage the
    hard disk, causing loss of data or the inability to start up from the hard disk.
  11. -tWv- macrumors 68000


    May 11, 2009
    Thanks for the tip! I'll be using this to change the sleep setting on my Mac.
  12. dsio macrumors regular

    Jun 19, 2011
    Disregard that...
  13. Performa636CD macrumors member

    Dec 12, 2006
    Cair Paravel
    Carrying my 12" G4 PB after putting it into sleep mode chewed up hard drive disks like it was nobody's business. I lost 2 HDDs in about 1 year until I figured out that either: I wasn't waiting long enough for the disks to stop moving before carrying my PB, or sleep mode was not safe for me to be carrying around my PB in a messenger bag.
  14. dsio macrumors regular

    Jun 19, 2011
    You'll find moving it wasn't the cause of your failure, the 12" G4 Powerbooks were fitted with known defective hard drives, usually Hitachi's in the range of 60-80GB which were known as the most failure prone hard disks in history. You could have waited until it had completely shut down, then transported it on a satin cushion and it still would have died.
  15. getz76 macrumors 6502a


    Jun 15, 2009
    Hell, AL
    From experience, I would not bother trying to change your friend's behavior. Just deal.
  16. Performa636CD macrumors member

    Dec 12, 2006
    Cair Paravel
    Hmmmm, I didn't know that. However, ever since I stopped moving the PB until it was completely shut down, I've had no HDD problems. It's been about 5 years since I replaced the HDD.
  17. dsio macrumors regular

    Jun 19, 2011
    Thats most likely because by then the bad disks were no longer in the channel, or your current disk probably isn't one of those bad travelstars.

    It's the disks back then that were the problem, a more recent one is probably fine. There are whole data recovery businesses around the world that built their business on those piece of crap hitachi drives, IBM, Dell, Apple everyone used them as OEM parts.
  18. Prodo123 macrumors 68020


    Nov 18, 2010
    I haven't encountered this problem because my MBP goes to sleep too fast, but I do what your friend suggests anyway.

    A light that stays on indicates that the hard drive platter is still spinning. If you've ever carried a laptop with a spinning CD inside, you'll notice that when you take the CD out it'll be full of micro-scratches. In a similar way, giving the hard drive any sort of impact will damage it. A lightweight task like simply lifting the laptop will not do damage to even contribute to a problem, but walking will give your computer slight, repetitive shock which sometimes cannot be detected by the sensor inside.

    When the light starts fading, it means the hard drive has been stopped and turned off. That is when it is COMPLETELY safe to handle the computer.

    SSDs are much more shock tolerable. You could probably throw a SSD (not recommended) and it would still contain data, given that none of the chips were chipped.

    Best advice: Keep a computer with any moving parts except the fans as stationary as possible for the longest life.
  19. grahamnp macrumors 6502a

    Jun 4, 2008
    HDDs shouldn't be jostled around although they can take some movement. The blinking light indicates that the RAM is being copied to the HDD and yes, this is when it is "vulnerable" but the sudden motion sensor will lock the drive head if there is too much movement and this prevents damage. Unfortunately, this means you computer never fully goes to sleep correctly. I just disable safesleep, mostly because writing to the HDD takes too long.
  20. marc11 macrumors 68000

    Mar 30, 2011
    NY USA
    I still cannot understand why all the advice to disable anything that saves a few seconds. Why not just wait 5 seconds for it to go into safe sleep mode, that is what it is there for??? If that is too slow, get an SSD, no worries of movement and when you close the lid it is sleeping almost within a second.

    But really, just close the lid, count to 5 or 10 and go....is it THAT big of a deal really?
  21. gr8tfly macrumors 603


    Oct 29, 2006
    ~119W 34N
    Just a correction: the sleep indicator is steady while dumping RAM to the HD. Once complete, it starts the "breathing" pulsation indicating sleep.
  22. elpmas macrumors 68000


    Sep 9, 2009
    Where the fresh snow don't go.
    He's too cautious...and ana* about it. This is where people assume Mac users are ana* people...
  23. munkery, Aug 19, 2011
    Last edited: Aug 19, 2011

    munkery macrumors 68020


    Dec 18, 2006
    Laptops with a triaxial accelerometer use the feature to detect motion to lock the head on the hard drive to help prevent damage but this is not 100% effective. Mac laptops have this feature but not all laptops have a triaxial accelerometer.


    When a laptop goes to sleep, the head is parked to prevent damage but there are instances where a laptop will wake from sleep on it's own. If this occurs while the laptop is being moved, then damage to the hard drive is possible.

    Some functions of software, such as alarm clock features, can cause laptops to wake from sleep on their own.

    If a laptop is only being moved a short distance, then waiting for it to sleep is sufficient to prevent damage.

    If the laptop is going to be moved a long distance such as in a backpack, then it should be turned off to further guarantee the prevention of damage.

    Powering down the machine has security benefits as well.
  24. Ulf1103 macrumors 6502

    Jan 5, 2011
    Well, but if you use an ssd, there will be no problem at all :p
  25. dusk007 macrumors 68040


    Dec 5, 2009
    There is also always the a chance the HDD will fail for no reason at all and it is probably a higher chance than the SMS failing, which in turn wouldn't mean the HDD gets killed it just means a little less extra protection.
    BTW. The SMS doesn't really help much when moving the thing around because it shouldn't even get triggered at such low G.

    What some people need to realise is that those HDDs were built to with stand the use in a Train. Most anybody should know these old crappy trains that just shake you around and guess what using a Notebook on them is possible without damaging anything.

    Too many people are too anal about to many things. If you stop worrying about all that stuff, you gain both time and happiness.

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