Need help - iMac

[JoshBoy]

Ok.... so mid year I went to go use my iMac, it’s a 27inch i5 3.4Ghz with 32gig ram and a 3 TB fusion drive. The computer stays on 24/7 as my media library streams to my Apple TV’s.
when I went to use it I couldn’t, it was soooo slow it was not usable at all. I tried reinstalling and that stuffed up (kept getting errors on the formatting).
I then purchased an external thunderbolt drive to see if it was the computer or the HDD on the way out, did the install and same problem. I was now able to format the internal drive and did a clean install with no time machine to see how it runs and it’s still really slow (not as bad as before but not really usable as a computer).
I have run the diagnostics at boot and everything says it’s all good. Disk utility says it’s all good. The RAM passes as well. Considering I have now tested abooting off thunderbolt (that should be just as quick as internal) and it’s still so sluggish, has anyone got suggestions or ideas on where to from here??

 

[JoshBoy]

And just to add, as at this morning it starts up to the loading screen and now shuts off. Ran diagnostics again and says it’s ok

 

[3SQ Machine]

Unfortunately you're going to have to do some digging in the activity monitor to look for any processes hogging up the system.

In your "original" user, switch among RAM usage, CPU, Network, etc. to see if something is bogging you down. Use the CPU usage screen to see if one core is overloading (some programs are dependent on a single core). I've found that some of my syncing services (e.g. google drive) will really bog the system when it's busy--something about the combination of network + CPU that creates spinning beach balls. I have 24GB of ram. Sort the processes by usage.

If you've got 3TB maybe you have enough to create a "new" clean "test user." Probably do that on the external thunderbolt drive--is it NVME? If you're using an external SATA drive it may "feel" slower than the fusion drive. Do a clean install of macOS on the external, create a brand new user, and DO NOT MIGRATE anything. Start adding/reinstalling applications one at a time. Use activity monitor to see if one of those programs starts using resources, especially if one core begins to spike or your ram gets full and starts swapping.

First see if it's a CPU issue and then start looking at other CPU hogs in your system to start disabling them. Apple has been busy finding ways of using background tasks to soak up our processors for its AI icloud services and other "features."

 

[JoshBoy]

Went through the activity monitor and nothing found (that was one of the first places I went to). This is driving me nuts and now with it not even booting up now (turning off at boot screen) I’m stuck for ideas.
I’ll try another new fresh install on the external without time machine (as I did do with the internal) and see if that does anything.

 

[3SQ Machine]

Yeah no boot is worrisome--can you boot from the external ssd? I hope it's not a motherboard issue.

One other thing -- are you using third-party ram? If so, maybe remove that and try the original apple ram as a test, if you still have it. Running Mojave or Catalina?

 

[rpmurray]

What year is your iMac? And which macOS are you using? Mojave?

 

[HDFan]

not even booting up now (turning off at boot screen)

When it boots when does it turn off?

Before Apple Logo (Firmware—At this stage, the Mac hardware is tested and initialized, and the booter is located and started.)

During Apple Logo (The booter loads the macOS kernel and essential hardware drivers, known as kernel extensions (KEXTs), into main memory and then allows the kernel to take over.)

Progress Bar under Apple Logo (The kernel provides the macOS foundation and loads additional drivers and the core BSD UNIX operating system.)

2nd progress bar (After the core operating system is loaded, it starts the first nonkernel process, launchd, which loads the rest of macOS. During this stage, you see a progress bar under the Apple logo on the main display. When this stage successfully completes, you see the login screen or the Finder, depending on whether FileVault is enabled or you are set to automatically log in.)

[from Apple Pro training series, MacOS Support essentials 10.14 on Safari Books online)

can you boot from the external ssd?

If that works then it would point to a drive failure. Assuming your have done clean reinstalls (wiped disk, installed OS and nothing else, and booted) on the internal drive and both the internal and external boots fail sounds like a hardware issue.

 

[JoshBoy]

When it boots when does it turn off?

Before Apple Logo (Firmware—At this stage, the Mac hardware is tested and initialized, and the booter is located and started.)

During Apple Logo (The booter loads the macOS kernel and essential hardware drivers, known as kernel extensions (KEXTs), into main memory and then allows the kernel to take over.)

Progress Bar under Apple Logo (The kernel provides the macOS foundation and loads additional drivers and the core BSD UNIX operating system.)

2nd progress bar (After the core operating system is loaded, it starts the first nonkernel process, launchd, which loads the rest of macOS. During this stage, you see a progress bar under the Apple logo on the main display. When this stage successfully completes, you see the login screen or the Finder, depending on whether FileVault is enabled or you are set to automatically log in.)

[from Apple Pro training series, MacOS Support essentials 10.14 on Safari Books online)



If that works then it would point to a drive failure. Assuming your have done clean reinstalls (wiped disk, installed OS and nothing else, and booted) on the internal drive and both the internal and external boots fail sounds like a hardware issue.

It’s the progress bar at about 70% it turns off.
it’s a 2014 iMac, going to try back on the external with fresh install.
has Mojave’s on external and cat on the internal.
[automerge]1577073048[/automerge]

What year is your iMac? And which macOS are you using? Mojave?

Both Mojave’s and cat. It’s 2014

 

[JoshBoy]

Quick update. I was stuffing around all night, I ended up wiping my external and placing a copy of Cat into it via my MacBook Pro. I then actually unplugged my second monitor as well and it is now running fine. I have a feeling it may be the graphics card that could be causing all the problems and it can’t handle the second display.
mom now running a fresh copy and will spend the next week doing a fresh install of all apps and pull my saved library’s from time machine (for things like Lightroom etc)

let’s hope this works.