iMac freezes while using external hard drive as main drive

Discussion in 'iMac' started by Sensamic, Jun 6, 2010.

  1. Sensamic macrumors 68030

    Mar 26, 2010

    Lately I've been using my external hard drive as the main drive of my imac I5 and every day it freezes when I open 3 or 4 apps or more or while doing several stuff at the same time. This, obviously, doesnt happen when using the internal hard drive of the imac, so I suppose is due to using firewire 800 or usb 2.0. Is it normal for every external hard drive to freeze when using it as the main drive or maybe is it that my external hard drive is bad?

    I'm planning on buying a more quieter external hard drive to use as the main drive of my imac, but I wont do so if it also keeps freezing every day. Any suggestions? Is it normal even when using firewire 800?

    When using the external hard drive I umount the internal drive of the imac. Maybe this is the reason?

    Its a Lacie Big Disk 500GB.

    Would an external SSD make a difference or would it still freeze?

  2. DisneyRicky macrumors regular


    Jun 5, 2010
    Northern California
    I really don't recommend using an external hard drive as a main source. I believe they run at a slower speed and they aren't the same design at all. Main reason for the freezing is that the computer needs a special type of hard drive. Probably a different hard-drive type. Isn't the standard for an external FAT and an internal is SMD or something?
  3. rnb2 macrumors regular

    Jan 23, 2006
    West Haven, CT, USA
    I definitely wouldn't run off of a USB external. FW800 should work okay, so I'm not sure why you are getting the freezing issue there.

    Also, I don't know why you are unmounting the internal drive - just set the boot drive in System Preferences > Startup Disk.

    I've been booting my i7 iMac off of an Intel X25M 80GB SSD in an OWC external FW800 enclosure since I got it in March, and it works great. An SSD will easily outperform a normal hard disk in a FW800 enclosure, since seek time and latency are almost nothing on the SSD (that means you're not waiting for platters to spin and the read head to find the data you asked for). Also, while an SSD in a FW800 enclosure won't be as fast as an internal SSD, it still works very well, particularly if you only put the OS and Applications on the SSD, and keep your user folder on the internal hard drive.

    (I'm afraid I don't have any idea what DisneyRicky is talking about. Yes, external drives are generally slower than internal, but the design is the same - either spinning platters and magnetic read/write heads, or flash memory based SSDs. External drives can be formatted just about any way you need to format them, though it is true that many may come formatted FAT32 for Windows compatibility. OS X will force you to reformat in Mac OS Extended (Journaled) in order to use an external as a boot drive, which I'm sure you already know.)
  4. Sensamic thread starter macrumors 68030

    Mar 26, 2010
    So maybe my external hard drive is the problem?

    I formatted the external hard drive as Mac Os Plus (with registration). Is this the problem? I didnt saw the "extended (journaled)" option. Or are they the same option?

    I wanted to buy this solution: World Computing/MS8USSD120/

    120GB OWC SSD in OWC external FW800 enclosure. Would it work without the imac freezing? Would a normal hard drive in that same enclosure work without freezing the imac too?
  5. lstone19 macrumors member

    May 3, 2010
    I run my six-year old G4 iMac off a LaCie 2big in a RAID 1 configuration. Works just fine.

    When you say it freezes, do you mean completely and you have to reboot or just long pauses with the spinning beach ball?

    Anyway, it's certainly not normal. And it should work fine. Properly formatted, a disk is a disk is a disk.

    And ignore DisneyRicky. I too have no idea what he's talking about, particularly the bit about needing a special type of hard drive. As I said, once formatted, a disk is a disk is a disk.
  6. rnb2 macrumors regular

    Jan 23, 2006
    West Haven, CT, USA
    What language are you running on your Mac? The different format descriptions sound like they might be the same, depending on the translation (and please forgive me if I've jumped to the wrong conclusion - I don't recall ever seeing "registration" in the formatting options in English, but it may be a translation of "journaled").

    The SSD you are considering is excellent, but I'd probably spend $10 more and get this external enclosure instead: World Computing/MEQMSSD120/

    That's the one I have, and it will give you the option to run via eSATA (for even faster performance) if a future Mac supports it. Also, because it is made of aluminum, it dissipates heat better than the plastic enclosure - my SSD does get warm during normal use. The OWC SSDs are probably the best on the market right now - better than my Intel.

    I wouldn't recommend running a desktop computer off of a regular laptop drive in an external enclosure. Because of the smaller media, read and transfer speeds are slower than a similar capacity 3.5" hard drive. An SSD in either OWC enclosure will outperform any mechanical external drive.

    If your computer is locking up, your current external drive is probably bad, but if it just pauses occasionally, that may indicate something else - perhaps a bad cable? In either case, the SSD should cure the issue - if it doesn't, you have some sort of hardware problem. If I were you, I would run the Apple hardware diagnostics (on the 2nd install DVD that came with the iMac - insert it in the drive, restart the computer, and hold down the D key until it boots from the DVD). I had issues with my i7 iMac after I got it, and it turned out to be bad RAM - Apple swapped it out under warranty.

    Let me know if you have any other questions.
  7. Sensamic thread starter macrumors 68030

    Mar 26, 2010
    I'm spanish, so I guess "Journaled" is the same as "With registration" when formatting a hard drive.

    So if the problem is my external hard drive, would another external hard drive work with FW800? If I can avoid paying 500$ for an SSD better. They are very expensive, but I really like them. What I'm looking for is to have a quieter imac. I was planning on booting from a quieter external hard drive and then unmount the internal hard drive of the imac, which is very noisy to me. I was thinking of putting the external hard drive far away from where I are with a 3m FW800 cable or even more. That way I wouldnt hear the external hard drive.

    The problem is that I have done some tests with the Lacie Big Disk 500GB and it freezes all the time. By that I mean that the beachball appears at first and then the whole system freezes, forcing me to shut down the imac by force.

    If I buy a new external hard drive would this issue keep happening? Im not sure if the problem is my external hard drive, the cables (happens with both FW800 and USB 2.0.) or the imac. I dont think the imac is the problem.
  8. lstone19 macrumors member

    May 3, 2010
    Are you connecting it with that 3 meter cable now? Or is that what you're thinking about? I would use as short a cable as possible. There are maximum lengths and the shorter the better.

    As I said, this should work (and does for me). So try a different cable and then try a different drive. The spinning beachball means that task is not responding and one reason can be because its waiting for a disk operation to complete.

    (I have booted various Macintoshes off of various external disks including both FW400 (both line and bus powered) as well as FW800. Never a problem. Usually I do it for testing (clone, then test on the clone before risking the real system disk) but as I said, my G4 iMac runs off the external all the time and there has never been an issue.
  9. Sensamic thread starter macrumors 68030

    Mar 26, 2010
    Right now I have a very short FW800 cable connecting my external hard drive to the imac. Like I said, I even tried using USB 2.0. (just in case) and it keeps freezing.

    I think I'll call Apple support tomorrow and see what they tell me. Maybe I'll buy a new external hard drive to try again. Maybe my external hard drive is old and not very compatible with Mac. Who knows?

    I've used my external hard drive with the imac before without problems. This was when using it as a backup drive for my personal files. It had no problems.

    When booting from the external hard drive at first everything seems all right. I can open apps and search the web. But just a few minutes after everything freezes suddenly when I open two or three apps at the same time...

    So if I buy a new 7200rpm external hard drive and use it as boot drive I would be ok?
  10. lstone19 macrumors member

    May 3, 2010
    Calling Apple will get you nowhere. They will tell you that they don't support that. Support in that case means they won't help you do it because it's not their hardware. They may also say it's not a proper configuration. Doesn't matter - lots of unsupported configurations work, it's just nobody has officially tested it and blessed it.

    It does work. I've said that before but this is the last time I'm going to say it.

    You might also want to consider getting software to test the disk. I am no expert in those sort of utilities so hopefully someone else will weigh in with suggestions. I use Tech Tool Pro (rarely) but I know there are others.

    Even with a short cable, it still could be a cable problem. If you have another FW cable, try it.
  11. Sensamic thread starter macrumors 68030

    Mar 26, 2010
    Ok. I will try with another FW800 cable.

    A few hours ago I erased my external hard drive and tried to install again Snow Leopard, but this time is just did not work. Installation stopped and told me there was an error and that it couldnt continue.

    This probably means that is something related to the hard drive, right?
  12. smithrh macrumors 68020


    Feb 28, 2009
    Do you remember the error?

    This is sounding more like a disk issue... but it still could be something else.
  13. lstone19 macrumors member

    May 3, 2010
    Since you're getting the same results with both Firewire and USB, that pretty much rules out a cable or the port. Which leaves only the disk.

    But wait, you said it's a LaCie BigDisk. As much as I've been quite happy with their disks themselves, the power supplies for them have been the weak link. Enough so that after replacing a few, I now have three or four spares sitting on the shelf.

    I'm pretty sure the BigDisk uses the same power supply I've found to be a problem: Model ACU057A-0512 with a 4-pin round connector to the drive enclosure. If that is what you have, I would seriously suggest replacing the power supply first. The symptoms of a failing power supply will be a lot of drive errors.
  14. rnb2 macrumors regular

    Jan 23, 2006
    West Haven, CT, USA
    In addition to what others have posted, try running the hardware diagnostics as I mentioned above - when I had bad RAM in my iMac, there were long pauses where the machine just froze. No programs responded, sometimes for a couple minutes. Try it, just to eliminate the possibility of bad RAM.
  15. Sensamic thread starter macrumors 68030

    Mar 26, 2010
    Thanks for the help guys.

    The power supply of my Lacie external hard drive is a 4-pin round connector, so that may be the clue. Anyway, whatever the problem is, its almost completely sure that is due to the external hard drive and not the imac.

    I did the Apple Hardware Test (the long one) and everything was ok. No problems found.

    I've had many problems with this external hard drive with Macs. Yesterday I finally decided to buy the OWC Mercury on-the-go enclosure with 120GB SSD. Im sure it will work perfect. I'll receive it this week or next one and I'll post results.

    I have another power supply at home from another Lacie external hard drive I have. I will try using its power supply. I cant use that drive cause its 2TB full of files and I dont have anywhere else to backup them.

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