Mac running very slow with Catalina.

Hi west_jl,

Thanks for posting in Apple Support Communities. We understand that your iMac is running more slowly than expected.

First, we recommend checking to see how much storage space is available since a lack of storage can cause some issues. You'll find that from the Apple () menu > About this Mac > Storage.

If you have plenty of storage, check to see if any apps or processes are running at a higher CPU% than may be expected. You can check by going to the Finder > Applications > Utilities > Activity Monitor. Check out the Activity Monitor User Guide which links several great articles that will help you identify those apps.

We also recommend starting up in safe mode which prevents some software from loading. Testing in safe mode can help to isolate this to your user account or system-wide. Check out How to use safe mode on your Mac for details.

Take care.

Lots of old crud (some 7 year old) but nothing stands out as a reason foe being slow.

I would let it limp along until it dies. And then get a new one with the Apple processor.