2012 iMac suddenly acting slow, odd

PhillyGuy72

macrumors 65816
Original poster
Sep 13, 2014
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Philadelphia, PA USA
Yes, I know it's an old iMac, but it has been running fine for years.
It is still running El Capitan 10.11.6 - since this is older

This past Wed. night around 7:30pm, I noticed the pointer on my screen move smoothy as usual, but every 8-10 seconds it would severely slow down, stutter as if something big was running in the background taking up RAM. Almost felt like it was 'indexing." But what...I don't know? Checking Network monitor, I saw nothing unusual. As I opened Photoshop to work on some photos, the lag on the cursor became worse.

Space on my main HD is fine, about 668GB left of space out of 1TB. I ran virus, malware checks..nothing. Of course looking on Google a possible cause (and a fear) "Your HD may be failing" was one of the reasons "Mac was running slow" I already did a new Time Machine backup in case this is happening.

I've done PRAM, SMC resets. PRAM didn't do anything, but SMC seemed to work....but only for about 5min before the issue came back.

By that time I ended up turning off the iMac and calling it a night. Thurs., I booted up the Mac..seemed ok although I did notice the desktop screen, Icons took a longer than usual time to appear on my screen, we're talking 2-3 min! Not normal I think.

But the computer seemed ok all day, night.

Then yesterday, Friday. Felt sluggish again...and once again at 7:30, there goes the cursor again, acting choppy, sluggish.

So far today..eh, it just simply feels slower than usual. I did a Terminal command to check/repair permissions - something that is gone from the regular Disk Utility program now.. It fixed some issues.

I even checked router setting to see if I have unusual activity happening - (call me a tad paranoid, I have a new neighbor..that seems slightly odd, antisocial, I was wondering if he was stealing Wifi, so something else..not the case it appears.)

Another oddity is also "Sleep Mode" I put the iMac in sleep..
Usually the screen shuts off, after 30-40 seconds I will hear a "click" meaning the HD turned off. BUT..I kept hearing this "click" every 2-3 minutes like this HD shutdown was on a loop. When I woke up my iMac, it wasn't asleep - reason I can tell is because my WiFi icon was still on (usually that animates to connect back to wifi after "waking up.")

Right now I'm baffled.
 

phunigai

Suspended
Nov 12, 2018
193
187
did we clear web browser history and cache?
and i had faulty usb mouse/ battery problem in the past that scrolled everything that could be the cause.

sometimes i need to unplug my 2012 mac mini and let that sit for 10 seconds then restart.

i hope this helps
 

vertical smile

macrumors 601
Sep 23, 2014
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This sounds somewhat similar to the problems I had on my Late 2012 27" iMac when my 1TB Fusion Drive started showing failure issues.

It took about 8 months to a year for a total failure. It started out with very minor issues that I would hardly notice. It would slowly corrupt the system to the point that it wouldn't boot and I had to reinstall the OS.

Each time this happened, the symptoms would start to show sooner and sooner. First a few months, then a few weeks, then days to corrupt the drive.

I had Apple Care at the time, but Apple refused to fix it due to it passing their HW Diagnostic tests. I had it in the Apple Store many times, once they kept it for over a week doing extended tests, but it kept passing. Eventually, it totally died, with 12 days left on my AC warranty, and they finally fixed it.


I am not saying that is what is going on with yours, but this is how it started for me.
 
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BrianBaughn

macrumors 603
Feb 13, 2011
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Baltimore, Maryland
Whether it's a standard 1TB drive or the optional 1TB Fusion drive I'd be surprised if it isn't the hard drive failing.

There are no free Mac utilities I know of that can scan for bad blocks. Maybe someone here knows of a bootable (USB thumbdrive) utility that could perform the scan on a Mac. I've never looked into it.

If the hard drive is failing are you prepared to put another one in? That would be the best solution. However, a USB 3.0 external SSD drive would probably give you better performance than you've ever experienced if the hard drive you currently have is a 1TB 5400RPM non-Fusion type.

You've made a backup...which is good. However, Time Machine doesn't report corrupted files. It just copies them to the backup. You can see the problem with this...migrating from the backup, if you ever do it, could bring corruption back to a fresh install.
 

RUGERMAN

macrumors regular
Jun 12, 2010
189
9
Whether it's a standard 1TB drive or the optional 1TB Fusion drive I'd be surprised if it isn't the hard drive failing.

There are no free Mac utilities I know of that can scan for bad blocks. Maybe someone here knows of a bootable (USB thumbdrive) utility that could perform the scan on a Mac. I've never looked into it.

If the hard drive is failing are you prepared to put another one in? That would be the best solution. However, a USB 3.0 external SSD drive would probably give you better performance than you've ever experienced if the hard drive you currently have is a 1TB 5400RPM non-Fusion type.

You've made a backup...which is good. However, Time Machine doesn't report corrupted files. It just copies them to the backup. You can see the problem with this...migrating from the backup, if you ever do it, could bring corruption back to a fresh install.
If you have a good backup you might try a recovery install of the OS the copy back your files from the bu. Then reinstall your SW. I did that with a 2010 MBP and it was as good as ever and I was running Hi Sierra just fine
 

Fishrrman

macrumors P6
Feb 20, 2009
17,474
5,675
OP:
Have you tried:
1. Boot to the recovery partition (command-R at boot)
2. Open Disk Utility and run "repair disk" on the internal drive.
3. What results do you get?
 

PhillyGuy72

macrumors 65816
Original poster
Sep 13, 2014
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Philadelphia, PA USA
Sorry it took so long to get back. The issue has been off and on for the past week. Sleep mode doesn't really "sleep" - When I hit sleep, the screen goes off...I'll head the "click" of the hard drive go off about 15 seconds after that...which is normal. But the "click" will repeat every 45-60 seconds. It's just odd!

I tried a slew of various checks. The Disk Utility on 10.11.6, El Capitan doesn't have a "repair disk" option, just First Aid. That seemed to look normal, no errors. I'll try the Command-R, recovery partition Fishrrman.

So do I feel the hard drive is starting to fail? Sadly yes. It happened once before with this iMac, just one day it wouldn't boot, the hard drive was totally dead out of nowhere. Thus was 7 months after getting it so that was covered, replaced..
[doublepost=1551487533][/doublepost]
Whether it's a standard 1TB drive or the optional 1TB Fusion drive I'd be surprised if it isn't the hard drive failing.

If the hard drive is failing are you prepared to put another one in? That would be the best solution. However, a USB 3.0 external SSD drive would probably give you better performance than you've ever experienced if the hard drive you currently have is a 1TB 5400RPM non-Fusion type.
Yes, if this does totally fail, I'm sure I will have no problem installing a new, better SSD drive. I have a copy of El Capitan on a CD to do a fresh OS install and just start over.

Yeah..I'll probably have to find a DIY video on You Tube, but it won't be an an issue. I have used YouTube videos in the past for computers, my drone..cars. etc. And taken this specific iMac apart before---carefully----to get rid of a lot of dust that built up inside, clean the fans, etc.

Wonderful (sarcasm) downfall of living in an old home, lot of dust in this place!
 

Wickintime

macrumors newbie
Feb 27, 2018
25
7
Melbourne, Australia
I had similar symptoms on my 2012 iMac and so I downloaded DriveDX which promptly advised my drive was failing! The Start/Stop count was 58,000 which gave 43% life remaining and the Power Cycle count was the same, but the Load Cycle count was at 1,518,242 with 1% life remaining!! Apparently a typical life for Load Cycle count is between 300,000-600,000. Needless to say I swapped out the HDD for an SSD very quickly. The job was quite straightforward and probably took me about 40 mins. Most of the time was spent clearing 6 years of dust from the fan. I had no problems with the screen removal/replacement using the OWC kit. Now it runs Mojave like a dream.
 
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PhillyGuy72

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Sep 13, 2014
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Philadelphia, PA USA
I had similar symptoms on my 2012 iMac and so I downloaded DriveDX which promptly advised my drive was failing! The Start/Stop count was 58,000 which gave 43% life remaining and the Power Cycle count was the same, but the Load Cycle count was at 1,518,242 with 1% life remaining!! Apparently a typical life for Load Cycle count is between 300,000-600,000. Needless to say I swapped out the HDD for an SSD very quickly. The job was quite straightforward and probably took me about 40 mins. Most of the time was spent clearing 6 years of dust from the fan. I had no problems with the screen removal/replacement using the OWC kit. Now it runs Mojave like a dream.
Thanks for mentioning that program. I downloaded it and on a trial version.
I did get a few indications of a "Pre-Fail" on the drive. :(

If you don't mind me asking, what SSD did you end up buying? I think I just may pick one up today, or order one online.
ANYTHING but a Seagate, I've had nothing but bad luck with them.

 

Fishrrman

macrumors P6
Feb 20, 2009
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OP:

Does the iMac have USB3?
(I'm not sure if ALL the "2012" iMacs did)

If so, you could do this:
1. Buy an EXTERNAL USB3 SSD
2. Set that up to become the boot drive (VERY easy to do)
3. Erase the internal drive and use it for backup and extra storage.

If you do it this way, you don't have to break open the iMac.

Then again, if you're comfortable "going into it", do it that way.
 
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vertical smile

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Sep 23, 2014
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Does the iMac have USB3?
(I'm not sure if ALL the "2012" iMacs did)
If it is a Late 2012 iMac then it does have USB3.

But, you bring up a good point, some people misclassify their Mac models and just state the year they buy them. If it is actually the Mid 2011 iMac, then it has USB 2.1 and swapping the HDD for a SSD would be pretty easy.

The OP also never stated if it is just a HDD, or a Fusion Drive.

If so, you could do this:
1. Buy an EXTERNAL USB3 SSD
2. Set that up to become the boot drive (VERY easy to do)
3. Erase the internal drive and use it for backup and extra storage.

If you do it this way, you don't have to break open the iMac.

Then again, if you're comfortable "going into it", do it that way.
To the OP: regardless of the actual model of the iMac (Mid 2011 or Late 2012), you can do @Fishrrman suggestion, but with a Thunderbolt drive.

You would have more and cheaper options with the USB3 though.

If you decide to go the Thunderbolt route, I will tell you what I did. I found a really cheap, but used Lacie Rugged Thunderbolt drive that came with a HDD. I swapped the HDD with a SSD, it only took about 3 minutes.
 

PhillyGuy72

macrumors 65816
Original poster
Sep 13, 2014
1,349
876
Philadelphia, PA USA
OP:

Does the iMac have USB3?
(I'm not sure if ALL the "2012" iMacs did)

If so, you could do this:
1. Buy an EXTERNAL USB3 SSD
2. Set that up to become the boot drive (VERY easy to do)
3. Erase the internal drive and use it for backup and extra storage.

If you do it this way, you don't have to break open the iMac.

Then again, if you're comfortable "going into it", do it that way.
I took a look at the "USB DEVICE TREE" actually shows USB 2.0.
I saw the benefits of this, External SSD AND USB 3, I know it's faster thats for sure and it would life easier. Not sure if I have that option right now.

Still digging into these SSD, the DIY kid for Crucial is nice, the adapters, cables, etc. Man do I need to built up so patience after looking at these DIY YouTube videos. I know I CAN do it, it does looks slight intimidating. I've taken it apart before (LCD screen) just to get blow out the dust, the screws involved a ton of cables, connections to get access..it's a bit scary I admit, getting involved with this would be my first. I love Macs, I will say it - when my old PC's failed (which happened more than a few times), opening the tower and swapping, adding stuff was very simple, less cramped. Still...I'll never go back to a PC...ever! :)
 

vertical smile

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Sep 23, 2014
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I took a look at the "USB DEVICE TREE" actually shows USB 2.0
IIRC, my Late 2012 iMac says this same thing, but it does have USB3. It shows up USB 2.0 because the keyboard is plugged in, and has two USB ports on it.

Do you have an Late 2012 iMac? When did you buy it?
 

PhillyGuy72

macrumors 65816
Original poster
Sep 13, 2014
1,349
876
Philadelphia, PA USA
IIRC, my Late 2012 iMac says this same thing, but it does have USB3. It shows up USB 2.0 because the keyboard is plugged in, and has two USB ports on it.

Do you have an Late 2012 iMac? When did you buy it?
Weird! I bought it in August 2012. I have a few external drives attached to this, I never noticed a speed difference - or paid attention. BUT one of my older USB storage devices I picked up cheap is a 3.0, I did notice the higher speed transfer on that.

I did pick up the Samsung Evo 960 1TB internal SSD today, it's on sale at Best Buy so I gave in. I used this SATA to USB 2.0 adapter I picked up off Amazon years ago, that worked perfectly. Already formatted and did a CMD+R installing a clean OS onto the new SSD. So far so good.