My Mac mini is very slow. The "rainbow wheel" is constantly spinning, ugh! Any suggestions? Fyi, I don't believe it's my internet connection, as my iPhone and iPad both run smoothly and without lag on my wifi connection at home, if that helps in any way with your answer. TIA!
Mac mini, macOS 10.14
Run EtreCheck and post back with the results.
https://itunes.apple.com/us/app/etrecheck/id1423715984?mt=12
I just cured mine of same problem, from advice on here.
An item 'DataclassOwnersManager' was the problem.
It was noted in the activity monitor and seemed to be on the login of another user who was not logged in.
It used a very large amount of CPU capacity.
On the other messages on here the fault had seemed to start coincident with a Mojave update.
My mini appears to be fine now.
Good luck.
Slow Mac Mini
