Xcode 12 GM seed uses 100% CPU

How much ram in your MB?

Did you restart and try again?

Ever since installing the Xcode 12 GM

Wonder if 12's sails are more trimmed when running under a release version of BigSur...

@devinthecold: No, for me the process taking 100-160% CPU is Xcode, for the entire time it's open, even when I'm not touching it. If I switch back to Beta 6, Xcode uses 0% when idle. I can switch back and forth between them and see the same behavior consistently.

@KMT: 32 GB ram. 2.9 GHz 6-Core Intel Core i9. I have tried rebooting and the behavior didn't change.

I've filed a feedback to Apple: https://feedbackassistant.apple.com/feedback/8701240

32 GB ram. 2.9 GHz 6-Core Intel Core i9.

Good info, thanks.

As a data point, running Xcode 12 GM on a soon-to-be-obsoleted late 2012 mac mini w/16 GB ram, it consumed shockingly little CPU, single digits, and less than 300mb ram when handling a simple hello world project to an iPhone 8. I then built a legacy mid-sized project, and while the machine load remained low, it took it's time walking thru/indexing 125 tasks, finally completing with no other drama.

The mini remained responsive as well. Definetly a contrast over previous versions. Quite the surprise, actually.

Doesn't help you of course, but hopefully whatever is going on comes down to bugs that can be squashed soon.

Good luck.

I had the same problem but it went away after a while. I assume it finished some background work after installation.

I have exactly the same issue, to the point every keystroke I press request up to 2 seconds to be taken into account. The simulator seems also to wait for XCode availability to process, so it is nearly impossible to run and debug our apps.