iMac Slow to the Point of Being Unusable - Hard Drive Check Says it's Ok

Discussion in 'Mac Basics and Help' started by benh911f, Feb 28, 2017.

  1. benh911f macrumors 6502

    Mar 11, 2009
    For the past week or so, my 21.5 Mid-2010 iMac has been almost unusable. It hasn't been fast for a while, due to the age, but this is on another level. One thing to note: since I did a fresh install of Sierra months ago, anytime I boot up the computer, I get a grey screen with progress bar that takes forever to load up.
    I have tried booting into safe mode, but that doesn't seem to work. After the 30-45 minutes it takes to boot up, any action I try to take on the computer takes several minutes at least to get going. I would like to transfer some things I have on there to an external hard drive, but even that seems impossible at this point. Trying to move my Photos library to an external drive, 45 minutes later the progress bar still says "preparing to move."

    Here are a few things I've tried doing:
    Reset PRAM, NVRAM and SMC
    Check the SMART status of the hard drive, which came back as verified
    Run disk utility on the hard drive, which reported no issues.

    Is it still possible the hard drive is failing? I'd like to try other things to fix it, but any action is basically impossible at this point. I ordered the kit and SSD from OWC to see if that helps, but I wish I could know for certain before I install it if that is the issue.

    Thanks for any help.
  2. bcave098 macrumors 6502a


    Sep 6, 2015
    Northern British Columbia
    It's very likely it is the hard drive. Disk Utility can only find errors with volumes and can't detect many hardware issues. Installing an SSD will make the computer feel like new, however.
  3. benh911f thread starter macrumors 6502

    Mar 11, 2009
    Thank you for the response. Considering most tasks are basically impossible now, is it likely I will lose the things on my main hard drive I haven't backed up?
  4. Mikael H macrumors 6502a

    Sep 3, 2014
    It completely depends on what (if anything) is wrong. It's always a bad idea not to have up-to-date backups of data you don't want to lose - multiple backups if it's critical data. I'd say get a sufficiently large USB drive, enable TimeMachine backups to it, and be patient until you have completed a backup run. Then consider possible upgrades.
  5. benh911f thread starter macrumors 6502

    Mar 11, 2009
    The majority of things are backed up, just some recent things over the past few weeks. Unfortunately, Time Machine doesn't seem like it will even boot.
  6. gnasher729 macrumors P6


    Nov 25, 2005
    One possibility that I have seen is that the Startup Disk has been set incorrectly, to a hard drive that doesn't exist. So when your Mac starts, it looks for a while for a hard drive that just isn't there. System Preferences -> Startup Disk.
  7. benh911f thread starter macrumors 6502

    Mar 11, 2009
    That checked out ok.
  8. CoastalOR macrumors 68020


    Jan 19, 2015
    Oregon, USA
    Have you tried booting into Recovery (hold command+r at start up)?

    What was the last OS version used on your most recent Time Machine backup? If not El Capitan, you can boot into Recovery from the TM drive using the option key at startup. It will be a little slower (assuming your external TM drive is USB2 speed and your TM backup/drive is direct connected to the Mac), but it should be faster than 30-45 minutes. Hopefully starting from the external successfully should give you an idea about your internal drive.
  9. RedTomato macrumors 601


    Mar 4, 2005
    .. London ..
    It's busy doing something. Maybe Spotlight is reindexing the disk?

    Have a look in Activity Monitor and see if anything is sucking up CPU time.

    With regard to moving the Photos Library, that is often a huge folder, so if the iMac is busy doing something else with the HDD, then telling it to do something else with the HDD will bog it right down. Try leaving it on without shutting down for a couple of days.

    A more geeky thing to check is to open the Console log (Applications / Utilities / Console) and take a look. Try not to be shocked, it's perfectly normal to see hundreds of error messages there, and most of them are routine and harmless. If the same message is being repeated dozens of times every second then that's an indication something might be wrong with something linked to the topic of the message.

    Things to check: iCloud and Internet services often cause slowdowns on older macs - turn off notifications, quit iCloud services, quit Facebook in System Preferences / Internet Accounts, log out / close quit as much as you can in Internet Services - these things hammer the HDD on older computers. One slow Mac I saw, something went wonky in Keychain Access, creating thousands of login accounts.

    Is the HDD full? that will slow down everything. Are there large Dropbox uploads/downloads waiting to be done?
  10. Garsun macrumors regular


    Oct 20, 2009
    If you have a second Mac with the same interface (firewire/thunderbolt) then one debugging/recover data method you might try is Target disk mode (boot by holding down the T)
    You can then plug the offending Mac into the working Mac and it will treat the offending Mac just like an external disk drive. This will allow you to copy over any files that may not be on the backup and also indicate whether or not it is a bad disk drive causing your issues.
    Hope this helps:)
  11. Fishrrman macrumors P6


    Feb 20, 2009
    Sierra is going to "run slow" on a 2010 iMac with a platter-based hard drive.
    That's just "a fact of Mac life".
    It's not going to run "fast" even on a healthy HDD.

    This is why I recommend that users of older Macs NOT use System software newer than OS 10.8 "Mountain Lion", UNLESS they have an SSD to run it from.

    Things will probably go better with an SSD installed.

    The problems the OP is having is yet one more example of why I always ALWAYS ALWAYS recommend that Mac users keep at least one external drive with a bootable cloned copy of the internal drive (created with either CarbonCopyCloner or SuperDuper). As the OP reports, TM isn't of much use in a situation as he is now in. He can't boot the Mac, he can't run the Mac.

    With a CCC cloned backup, he could be doing both.
  12. kschendel macrumors 65816

    Dec 9, 2014
    Older Macs with HDD's aren't the quickest way to run Sierra, but response time in minutes is not to be expected. The OP has something seriously wrong with the machine. I'd second the suggestion to try booting into Recovery.

    If you have a working machine with normal Sierra response times of kinda-slow, then yes, I agree that an SSD is very likely the answer. Also, 8 Gb memory if you have 4 or less.
  13. benh911f thread starter macrumors 6502

    Mar 11, 2009
    Thanks for the replies.
    I believe I tried booting into recovery but I don't believe that worked. I will try again in the morning.
    I did notice a bit of a slow down when I upgraded to Sierra, but the computer was still usable. This is completely beyond that.
    I actually always was good about having backups. I keep most of my media on external hard drives and have redundant backups, and also had another external connected for Time Machine. Within the past few months i hadn't been using the computer too frequently, and realized the other day that I had unplugged the Time Machine drive within the last few weeks, so if I'm able to finally boot the Time Machine app, we'll see when the last backup was.
    Sadly I don't have a second Mac so the other suggestion I won't be able to try.
  14. satcomer, Mar 3, 2017
    Last edited: Mar 4, 2017

    satcomer macrumors 603


    Feb 19, 2008
    The Finger Lakes Region
    Give the free application EtreCheck. Think of it like a system report on steroids showing you the path to manually delete old files & plugins that are not compatible with your upgrade!

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13 February 28, 2017