High CPU use caused by SystemUIServer?

systemuiserverI’ve been plagued by this issue for months now wherein the SystemUIServer daemon on Mac OS X 10.8.x has been consuming massive amounts of CPU. The visible results of this process acting up were:

  • Laggy performance in applications — Spotlight in particular
  • The clock not updating the time (switched to the iStat Menus clock to avoid this before I found the problem)
  • Using any menu bar application would result in extremely slow performance

This is the kind of thing that you don’t expect to really interfere with your use of the computer, but it shocked me that in some cases it would use as much as 90% of my CPU which severely affects performance.

Workarounds and “solutions”

I found a number of articles indicating the following:

  1. Workarounds: kill SystemUIServer and it’ll come back and all will be well. This is true for a few hours, but the issue kept coming back
  2. Solution: stop running 3rd party menu bar apps

The problem is that I love my menubar apps! So I went through each and every 3rd party menu bar app and updated them. Why didn’t this solve the problem? Because I didn’t truly update¬†all of them.

The cause: Dropbox

Yep, Dropbox was the cause of this problem.

Dropbox was the only application that ran in my menu bar that didn’t auto update in some manner (such as via Sparkle or the Mac App Store). It was certainly my own fault for not checking for updates myself, but for those of you who might dismiss Dropbox as the cause, you better head on over to their website and get updating!

Resolve it for good.

If you’re encountering this issue, update Dropbox along with any other menu bar apps you might have. Here are some that I use which were updated during my troubleshooting:

Hope this solves the problem for you too!


  1. Robin on July 19, 2013 at 10:16 pm

    Thanks, this helped!

    • Jordan on November 4, 2013 at 1:03 pm

      That’s great!

  2. viru on February 13, 2014 at 3:05 am

    In my case it was PostgreSQL app from http://postgresapp.com/ Restarting or quitting Postgres fixed the problem.

    • Jordan on February 19, 2014 at 6:52 am

      Thanks for the addition Viru! This issue can indeed be caused by many different menubar apps, so I’m hoping we’ll end up with a pretty exhaustive list that people can search through via this post and comments.

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