Tahoe has made my iMac unusable.

Part 1 of 3

We are speaking about this computer are we not ?

iMac (Retina 5K, 27-inch, 2020) - Technical Specifications

Depending on the exact Hardware Configurations of this computer

This machine should be just flying along nicely

I might suggest and based upon the user byline " iMac 27″, macOS 26.2 "

The latest version of macOS is 26.5. Learn how to update the software on your Mac and how to allow important background updates.

Part 2 of 3

To further Trouble Shoot

Restart the computer in Safe Mode 

Do the issues persist ?

Sometimes a Safe Boot followed by a Normal Boot will just put things right.

If not - there could be something in the main User Account playing up.

To further isolate this - Set up users, guests, and groups on Mac.

Then log out of the Main User account and log into the dummy account and test again if the issue persists.

If the issue is present in the dummy account - then, this appears to be a System Wide issue on the computer.

Part 3 of 3

To Drill Down further and to avoid a session of Q&A, Q&A  and Q&A  

Download the Application Etrecheck  ( External Link ) directly from the Developer.

The Application is Not a " Silver Bullet "  and is  only a tool to examine the Hardware / Software used on this computer 

This is a Diagnostic Tool that makes no changes to the computer Hardware / Software used on this computer 

The application is free or paid from added features. 

The Report will Not Reveal Any Personal Information. 

Post back the Full Report - Share Report >> Copy , then  paste  >>>> using the Additional Text Icon  <<<<

FredJung wrote:

I regret updating my 2020 Retina 5k 27" iMac to Tahoe several months ago. It has made my iMac practically unusable. In my activity Monitor, my CPU % goes up over 50% constantly. When I play my computer game 7Days to Die, it used to be 30-40 fps before updating. Now I am lucky to get 10 fps and it constantly goes down to 1 fps making the game practically unplayable. I made all the settings as low as possible. I am struggling with Photoshop as I have to wait to do ANYTHING. Even drawing a line is an impossibility. What can be done.

Typically an issue like yours is resolved by

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus

all known to cause issues on the macOS

FredJung wrote:

It works well in Safe Mode so it's an extension or background application. I had turned off many extensions and removed apps on my menu bar but still gets the high CPU usage. Will still keep at this mystery.

If you want us to help, please run Etrecheck and post its full report here. Use the "additional text" button and paste the report into the text box.

We are often able to notice the most probable culprits of issues.

The report does not include any private information - you can read it yourself before posting to make sure of that.

FredJung wrote:

It works well in Safe Mode so it's an extension or background application. I had turned off many extensions and removed apps on my menu bar but still gets the high CPU usage. Will still keep at this mystery.

Thank you for latest information

Working well in Safe Mode usually indicates some Third Party Software is playing up

Shall await your decision to use or not use Etrecheck application and then to post the Full Report

Should you decide to post it now or later

We or someone will probably have a look and offer some suggestions

leroydouglas wrote:

FredJung wrote:

I regret updating my 2020 Retina 5k 27" iMac to Tahoe several months ago. It has made my iMac practically unusable. In my activity Monitor, my CPU % goes up over 50% constantly. When I play my computer game 7Days to Die, it used to be 30-40 fps before updating. Now I am lucky to get 10 fps and it constantly goes down to 1 fps making the game practically unplayable. I made all the settings as low as possible. I am struggling with Photoshop as I have to wait to do ANYTHING. Even drawing a line is an impossibility. What can be done.

Typically an issue like yours is resolved by

Uninstall all third party apps that are Cleaners/Optimizers/VPN/Anti-Virus

idence

all known to cause issues on the macOS

I think we would get to that, once there is evidence of such useless software installed

Thanks for chipping in, though

FredJung wrote:

Yes. That is my iMac. Thanks for the reply. I will try this out. It has been a frustrating year screaming at my computer as it struggles to do things.

You are welcome

🦉-53