21.5inch iMac Has Bad Performance Issues, Need Help Figuring This Out

[Brandy-Boi]

So over the last several months my iMac (2015 4K model, I think a base model and is about 5yrs old) has been having some seriously obnoxious issues that are getting worse. It takes way too long to boot up, once you log into an account it takes maybe upwards of 10 - 15 minutes for any browser or app to start properly working, icons don't fully load for awhile, there's a lot of stuttering and performance issues I could go on about but I think you understand what I mean. It's been getting progressively worse over the last several months and before I make an appointment for an Apple Store check-up I was hoping to get some other advice for steps to try. I think I've tried just about every suggestion Apple told me (NVRAM reset, Recovery Mode, Disk Utility, Reinstalling OS...) but I was hoping to get some suggestions for other things to try that may help.

I think the storage is fine, about 400GB out of 1TB used and I'm still looking for more things to delete. Is it possible that there may be an abundance of useless files that could be causing issues? I mainly use the iMac for casual and simple stuff, in the last few months I've been using Logic Pro for recording audio (voice work) but they are simple recordings, and I've been trying to teach myself Final Cut Pro but I don't do anything serious or heavy demanding. I found a free version of something called CleanMyMac X, does anyone have any good experiences with that or another program that does something similar (weeding through old junk files) because I'm open to all suggestions. As long as CleanMyMac X doesn't remove things I want to keep or lets me see what gets deleted before I nuke it, I'll give it a try.

We've had this iMac for about 5 years, and we're really hoping to not replace it unless we absolutely have too. I'm doing a lot more work online and with its recent issues I'm worried it may crap out on me at the worst moments. I'm looking for any kind of advice for things to try before going in for an in store appointment so any and all suggestions based on what I said would be greatly appreciated.

 

[krbrock1]

I would try something simple to begin with. Setup a new user account in preferences. Reboot and login to the new account (you may have to login a second time, since the first will take a bit to initialize since it's a new account).

The point of this is to rule out system corruption, or an application behaving "naughty" in the account you're having issues with. A new account allows you to compare performance. If the new account seems to be working fine and you encounter the same problems when logging back into the old account you can almost bet you have a file / corrupt issue.

Personally I would stay away from CleanMyMac X in favor of a more robust open source system cleaner like OnyX. If you've never used it, it's a great app. I've been using it for over 10 years and just run the maintenance routine every now and again to keep my Macs running tight =)

–> https://www.titanium-software.fr/en/index.html

 

[Brandy-Boi]

I would try something simple to begin with. Setup a new user account in preferences. Reboot and login to the new account (you may have to login a second time, since the first will take a bit to initialize since it's a new account).

The point of this is to rule out system corruption, or an application behaving "naughty" in the account you're having issues with. A new account allows you to compare performance. If the new account seems to be working fine and you encounter the same problems when logging back into the old account you can almost bet you have a file / corrupt issue.

Personally I would stay away from CleanMyMac X in favor of a more robust open source system cleaner like OnyX. If you've never used it, it's a great app. I've been using it for over 10 years and just run the maintenance routine every now and again to keep my Macs running tight =)

–> https://www.titanium-software.fr/en/index.html

I'll definitely try out the new account test and see what happens! Never thought about trying that so thanks. I tried both in the end before you replied, CMMX has nice layout but the free version only deletes a tiny amount of old files and it seems too expensive when I'm still on the fence about it, and OnyX is unfortunately not compatible with Big Sur as of now so I can't try it out. Other people praise OnyX over CMMX so once they update it for Big Sur I'll jump right on it.

 

[Madcross]

What operating system are you working with? Catalina? Mojave?

 

[Brandy-Boi]

What operating system are you working with? Catalina? Mojave?

I always stay up to date, it's currently on Big Sur.

 

[UrsaMinor]

Go into Activity Monitor and check the CPU, Memory, and Disk usage.

With that said, the symptoms you describe are most often caused by a failing hard drive (especially the very slow boot before you even get to the user account(s). If you haven't backed up your data, you might want to do so. Actually, do this first if needed.

You can also run diagnostics by shutting down the mac, turning it on, then immediately hold down the "D" key until you're asked to choose a language.

 

[Brandy-Boi]

Go into Activity Monitor and check the CPU, Memory, and Disk usage.

With that said, the symptoms you describe are most often caused by a failing hard drive (especially the very slow boot before you even get to the user account(s). If you haven't backed up your data, you might want to do so. Actually, do this first if needed.

You can also run diagnostics by shutting down the mac, turning it on, then immediately hold down the "D" key until you're asked to choose a language.

I did look at the Activity Monitor but I couldn't understand what any of it meant. And I did recently buy a new hard drive solely for the Time Machine since the previous one crapped out. I backup regularly so that's not an issue. I did learn about that diagnostics the other day from a support agent and it said nothing was wrong, so that stumped me.

 

[DeltaMac]

I think the main reason your iMac is getting slower and slower is the 1TB hard drive. You said it was a base model iMac, and that would have come with a 5400 rpm hard drive.
Diagnostics won't find anything wrong, and there's nothing wrong with the hard drive, except that it is, well, a mechanical hard drive.
A 5400-rpm hard drive really struggles with macOS, particularly now that the drive will be formatted as APFS.
Your system would be much more responsive, running on an SSD.
You can actually try that out by installing Big Sur on an external SSD, plugged in to your USB port.
Once you see how much better that runs, you could replace the internal hard drive with an SSD.
However, many users simply use the external SSD as the full-time boot drive.
You do lose one USB port, of course, but it may be a useful change for you.
I have a 2014 iMac, with an SSD attached to the stand with velcro, and have used it like that for about 3 years.

 

[UrsaMinor]

Delta,

A 5400 RPM drive, nor a 5400 RPM with an APFS file system would cause the slowness that the OP described.. The problem has nothing to do with the fact that it's a base model iMac. The OP said:

"It takes way too long to boot up, once you log into an account it takes maybe upwards of 10 - 15 minutes for any browser or app to start properly working, icons don't fully load for awhile, there's a lot of stuttering and performance issues".


Also, Apple's Disk Health system is more file system based, and as such, not very thorough. In other words, drives that aren't performing at their physical best, can still pass that test.


Anyway, what I was getting at with my previous post, is similar to what you said. That is, replace the hard drive with a USB 3 external SSD and use Velcro to attach it. I've performed that exact same fix on many i-Macs, and it works extremely well.

Now the question is, would the OP want a new install of the operating system on the SSD and then use Migration Assistant to transfer the data and apps, or use a cloning method. I've used both methods depending on the situation.

 

[Fishrrman]

What KIND of drive is in it?
Is it a:
- platter-based hard drive
- fusion drive
- SSD (I don't think this would be it)

If it's a platter-based hard drive, it's going to be SLOW, regardless of how much "free space" is on it. There is NOTHING you can do to make it faster.

If it's a platter-based HDD, you have two choices:
Choice 1:
Open up the iMac and replace the HDD with a 2.5" SATA SSD.

Choice 2: (MUCH easier)
Buy an EXTERNAL USB3 SSD, plug it in, and set it up to become the new boot drive.

I would get an external USB3 SSD (either one that is "pre-built and ready to go", or a "bare" 2.5" SSD and an external USB3 enclosure).

Then, you're going to have to install a copy of Big Sur onto it.
Things would be MUCH easier if you WEREN'T using Big Sur, but cloning software currently won't work with it.

Then, "migrate" your data from the internal HDD to the SSD.

Then, set the SSD to become the new boot drive.

If you truly want "faster", this is what you're gonna have to do.
Again, there is NOTHING you can do to a platter-based internal HDD to "make it faster". It is what it is.

 

[Ruggy]

Go into Activity Monitor and check the CPU, Memory, and Disk usage.

With that said, the symptoms you describe are most often caused by a failing hard drive (especially the very slow boot before you even get to the user account(s). If you haven't backed up your data, you might want to do so. Actually, do this first if needed.

You can also run diagnostics by shutting down the mac, turning it on, then immediately hold down the "D" key until you're asked to choose a language.

 

[Ruggy]

It really does sound like a failing HD as said and it really shouldn't be acting like that even a base model.
You said you bought a new HD recently for time machine but is that inside the machine because the hardware diagnostic tools come on the original HD in a hidden partition and it's hard to see how you could have tested the drive if new because they won't be there so It's odd.
If you've got an external drive attached then unplug that and see what happens because that can cause all sorts of start up problems.
Alternatively, it's not difficult to clone a hard drive with an operating system on it and boot from the external drive.
If you've got a drive hanging around that would be a cheap option to test otherwise, smallish SSD are not expensive and should boot really well. I think you can create a bootable thumb drive too and that might help.

Then check out the internal HD with the diagnostic tools if you can. They are on the original installation disks too if you have them and can run them. It's really only useful to use the 'extended' or advanced options as otherwise it really doesn't find much.
But it's classic hard drive symptoms. It could be a cable or controller however.
And it would also be useful to click on the apple logo top left and check how much memory is working because it could be RAM.
But it's pecfectly feasible to run a Mac on an external drive really successfully without having to spend a fortune in repairs.
Otherwise, I think a trip into an Apple store and let them run tests on it. They should be able to tell you what's wrong without you having to pay for anything and it's most likely a hardware problem.
And although the older hard disks are slower, they shouldn't give you anything as bad as that.
Best
PS Something I didn't make clear: if you are using an external drive for a Time Machine backup it can give enormous problems if it isn't working properly. If it's trying to back up all the time, or if it has trouble finding the external drive or Time Machine is corrupt or something. Booting from an external drive is ok but Time Machine drives can cause problems.