Today AMPDevicesAgent started using 100% of my CPU. This is causing the fan to run all the time.

What is AMP Devices Agent

How can I stop this

  • 2
    See this, written by one of the mods on Ask Different, grg - georgegarside.com/blog/macos/… I think he probably deserves the credit for copy/pasting its essence to here, rather than me ;)
    – Tetsujin
    Commented Jan 23, 2020 at 12:10
  • CPU is still at 100% on Big Sur, and a late edition (11.6.6) at that. It's a conspiracy to get us to subscribe to iCloud plans :-).
    – Sam7919
    Commented May 31, 2022 at 20:44

1 Answer 1


I still had this nagging problem on Big Sur, so it does not appear to be fixed (thoroughly). The iPhone entry in my Finder was permanently stuck at about one third and AMPDevicesAgent permanently took more than 99% of one CPU. Although the system remained responsive I noticed the fan blowing and more activity than I expected in the monitor.

I ended up force quitting AMPDevicesAgent in the activity monitor which removed the iPhone entry from my finder and the activity returned to normal. However I wanted my iPhone to be backed up so I also restarted the finder. This ended up in similarly high CPU usage as before, but AMPDevicesAgent never reached the levels it used to have. After a fairly long period of time (about 20 minutes) and several iPhone unlocks when it appeared to be stuck the process eventually settled down and finished the backup.

Now my iPhone is backed up and it appears in the finder with the usual information. AMPDevicesAgent is back at 0.1% where it is supposed to be. So all appears to be normal again and I keep my fingers crossed. I only found little info on the subject in the "usual places" like StackOverflow an Apple community forums.

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