Why is my iMac 2020 is always running slow

1. As another user has posted, is the 5400 rpm drive part of the problem? Would a SSD help greatly?

Absolutely (huge difference).

Professional installation is highly recommended, especially since you may still be covered by Applecare if you bought it. Here are install videos:

https://eshop.macsales.com/installvideos/iMac-21-inch-2019/

Or, less expensive, take a look at above vendor and get an external SSD in an enclosure and use that as your every day boot drive. You can simply format it in Disk Utility, download CarbonCopyCloner, and have it create a bootable clone on the external SSD. You can then boot and work from it. Once you know everything is running perfectly, you can use the internal as a backup drive (after wiping it).

Hello Frithwood,

Thank you for using Apple Support Communities!

We understand from your post that when opening applications on your iMac running macOS Big Sur the rainbow wheel displays for several minutes before starting the application. We know how important it is for you to be able to access your applications quickly. This article has steps which may help:

If your Mac runs slowly - Apple Support

Best Regards.

Firth, thanks for the image and the reply of what you tried. A couple of next steps can be.

1. Create a brand new user. Does this new user have the same "slowness" issue and your current user account? If not then it is something in your current user configuration. You could log back in to your original account and start removing applications that are loaded when you login. Check the Users & Groups preference pane and the login items for your account. If so then there is something else causing the issue.
2. Make sure you have the latest versions of the software that is on your system. Especially login items. You can also change the order of the login items to see if that helps.
3. Another item that comes to mind. Do you have anything connected to your iMac? If so remove everything not absolutely necessary and start connecting them one at a time. And find what causes the machine to slow down.

Does your computer have a fusion drive in it? Or is it just a SSD?

I hope this helps.

Paul

Please post the entire report as follows:

Copy the report

and use the Additional Text button to include the report in your reply.

IMPORTANT:

Before running Etrecheck assign Full Disk Access to Etrecheck in the Etrecheck's Privacy preference pane so that it can get additional information from the Console and log files for the report:

Also click and read the About info to further permit full disk access.

Then we can examine the report and see if we can determine what might be causing the problem.

I'm sure that your image showed your specs of your computer. Can you repost them without your serial number? How much memory does your computer have? Also Etreckeck is a good app for troubleshooting.

Paul

Your main problem is that your model has the super slow 5400 rpm spinning drive unless you customized it at time of purchase - it does everything in a snail like speed. There is nothing you can do except get an external SSD, plug that in, create a clone of your system on it and then use that external as your regular boot drive.