Slow computer after Tahoe upgrade, remove launch items?

danthejan wrote:

I keep hoping to find the one thing that's causing this, fix it, and get on with my life.

Based on your Activity Monitor screenshot, kernel_task is using lots of CPU resources. It does that to cool down your Mac.

If kernel_task is using a large percentage of your Mac CPU - Apple Support

That means whatever was hogging your CPU had already been doing it for a while so macOS stepped in.

Restart your Mac, launch Activity Monitor and leave it open while you go about your business, but keep an eye on it. If something is over 100% CPU and stays there much of the time, what is it? (Side note: the denominator for % CPU is 100% per core, for example my M4 Pro MBP has 14 cores so full utilization would be 1400%.)

danthejan wrote:

I've removed the offending hard drives and added a brand new one.

Yes, that is good. But your WDC third party external drive software is still installed, is there a reason you can't uninstall it. Probably no longer an issue with the WD drives gone, but it is not a bad thing to remove unnecessary system extensions.

I deleted Chrome.

It looks like you have Firefox and Brave browsers active, is that the case? Depending on how many tabs or windows are open and if the sites they are on have active video in the background, they can slow down a computer.

I stopped using Time Machine.

That is probably not a good thing. I would resume TM backups, you may need them.

I keep hoping to find the one thing that's causing this, fix it, and get on with my life.

Often there are multiple things combining to create issues. You had some problematic external drives, one of which had failed and your Mac was struggling to deal with it. Those drives are gone now.

Some of those launch items appear to have been installed a long time ago, before Tahoe came out. I wonder if they have been updated and if so, are compatible with Tahoe:

com.muse.hubd.plist (Musecy SM Ltd - installed 2024-12-02)

Executable: /Applications/Muse Hub.app/Contents/Resources/hubd

Location: /Applications/Muse Hub.app

[Not Loaded] com.muse.museservice.plist (Musecy SM Ltd - installed 2025-03-08)

Executable: /Library/PrivilegedHelperTools/com.muse.museservice

Muse Hub has been a concern of some users who felt it created deep and hard to stop background processes that slowed down their Macs and also phoned home too much, using up bandwidth like a bit torrent app. Do you need Muse Hub? https://www.reddit.com/r/Musescore/comments/102iqmf/is_musehub_malware/

[Not Loaded] com.wacom.UpdateHelper.plist (Wacom Technology Corp. - installed 2024-06-03)

Executable: /Library/PrivilegedHelperTools/com.wacom.UpdateHelper.app/Contents/MacOS/com.wacom.UpdateHelper

Do you need the Wacom tools? Yours dates from 2024.

[Not Loaded] us.zoom.ZoomDaemon.plist (Zoom Video Communications, Inc. - installed 2024-12-18)

Executable: /Library/PrivilegedHelperTools/us.zoom.ZoomDaemon

Have you updated or removed and reinstalled Zoom?

I truly appreciate the help, but i'm awash in fixes and I wish I could go back and start over.

You can start over but I would not recommend doing that unless you make no more progress. To start over, you would need at least two verified and reliable backups, TM or clone backups (SuperDuper, CCC). Then you would follow these steps: What to do before you sell, give away, trade in, or recycle your Mac - Apple Support

This makes your Mac into an "as new" computer with no users and just a fresh MacOS. Then you would start it up and migrate from your backup user accounts and files but no other settings and no apps. Then test for normal operations, perhaps browsing with your preferred browsers. If ok, the install one or two at a time your software, leaving out things no longer in use or needed. Test after each installation.

I would not "start over" unless you really are finding no progress. I have done it on older Macs that I "inherited" from my daughter and it always resulted in a much "zippier" device, probably from questionable things I did not reinstall that she might have installed.

I and others in this Discussions forum have been running Tahoe on 2019 Macbook Pros, Intel machines, with 16 GB RAM. I find that mine is very responsive and yours I think should be better as you have an iMac Intel 2020 model, that should be a more powerful system, plus you have 32 GB RAM (my laptop is just 16 GB RAM).

When did you upgrade?

if recently (i.e. within hours, or possibly days), this is normal, since the OS takes time to reindex files on the file system rebuild caches, consolidate backups, etc.

It should settle down pretty soon.

If it's been longer than that, then something else may be amiss. Activity Monitor.app is probably the place to start, to see if there are any applications that are consuming excessive CPU cycles, memory pressure, etc.

Camelot wrote:

When did you upgrade?

if recently (i.e. within hours, or possibly days), this is normal, since the OS takes time to reindex files on the file system rebuild caches, consolidate backups, etc.

It should settle down pretty soon.

If it's been longer than that, then something else may be amiss. Activity Monitor.app is probably the place to start, to see if there are any applications that are consuming excessive CPU cycles, memory pressure, etc.

FYI, the OP has an existing thread here where we had already greatly improved system performance:

https://discussions.apple.com/thread/256238571?sortBy=oldest_first

danthejan wrote:

I'm so frustrated.

I keep hoping to find the one thing that's causing this, fix it, and get on with my life.

I truly appreciate the help, but i'm awash in fixes and I wish I could go back and start over.

Others have reported high CPU issues with the Brave Helper and Brave Browser.

see > https://community.brave.app/t/macbook-cpu-use-140-with-brave-no-usual-fixes-work/616937

and > https://community.brave.app/t/brave-using-too-much-power/616739

Brave might not be your only issue, but it's a good place to start given that both are reporting a large amount of CPU usage.

2 weeks should be more than enough time.

Activity Monitor.app is pretty straightforward - open it, and it will show you a list of processes, ordered by CPU load. Some of the entries will be obvious (e.g. application you're running), many will be unknown to you (background processes, system services, etc.), but you only need to worry about any that are taking more than a few percentage points of your CPU.

You can also switch to the Memory tab in Activity Monitor to get an overview of your memory usage. Don't worry too much about individual application, unless the memory pressure graph at the bottom shows you're using most of your system memory.

Yeah, your CPU usage is way high, especially for kernel_task.

There are a few possible causes for that.

What does the Memory tab have to say? If you're low on memory then the kernel could be working overtime tying to manage memory