As far as I know WindowServer process is used by all apps to draw windows that we see. And a lot of people are reporting a problem when their WindowServer is using a lot of CPU. Is there any way to find out what process is interacting with WindowServer besides looking at the precesses at the ActivityMonitor, shutting them down and looking at the result?

  • I was suffering from the same issue on my 2014 MacBook after upgrading to Big Sur (from High Sierra, upgraded from Mavericks over the years). I finally got fed up with it and decided to do a clean install, wiping everything and restoring just what I need from backup. Aside from clearing out all the cruft that accumulated on my SSD, the WindowServer issue is gone. Recommended, if you can spare the time for a clean install! Commented Aug 11, 2021 at 10:46
  • Update: while my MacBook does feel more responsive and the battery lasts longer since the clean install, WindowServer CPU usage still jumps to 25% when just moving the mouse pointer. Based on the number of reports I've found, I believe this is a bug in Big Sur. Commented Aug 31, 2021 at 21:53

1 Answer 1


Check out the man page for perfdiagnose. This tool is purpose-made for diagnosing exactly this sort of issue, where a simpler tool like Activity Monitor can only show you symptoms.

The output from perfdiagnose is not intended for end-users, but for developers and teams at Apple. If you're not able to make any sense of the logs it produces, your best bet is to attach them to a bug report submitted to Apple.

  • 2
    Awesome, I think it's just the thing I'm looking for. I'm kinda developer myself. Thank you
    – Uko
    Commented Apr 20, 2012 at 22:26
  • 1
    perfdiagnose does not appear in my path and there aren't any man pages on it (Mojave 10.14.6 (18G87)). Has it changed it's name? Is it somewhere NOT on the path?
    – drevicko
    Commented Sep 12, 2019 at 8:14
  • 1
    Now you need to do sudo sysdiagnose
    – Hari Honor
    Commented Aug 10, 2020 at 7:54

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .