High cfprefsd CPU usage when using MacID

Update 5: Apple have replied to my bug report informing me that it’s a duplicate of another bug (#24570370). When that bug gets marked as fixed I will be able to see it and update you accordingly, but until it does we’ve done all we can do at this point.

Update 4: Thank you to everyone who’s provided a Bluetooth diagnostic report, I’ve now forwarded them on to Apple with bug report #26194733. 

Update 3: Clearing the OS X Bluetooth cache should help, even if not permanently. To clear the cache, click the MacID menu > More > Reset Bluetooth. It shouldn’t affect any paired keyboards or mice but will clear the cache.

Update 2: Other apps that use Bluetooth APIs on OS X are experiencing the same issue. Hopefully Apple will have a fix for this in the near future. Other people have been filing bugs with Apple too.

Update 1: A user has been kind enough to email to let me know that after reinstalling El Capitan, it has fixed the issue for them. Not an ideal solution by any means, but does help prove the theory Apple can fix it.

There are a few people reporting that while using MacID, the system is reporting high CPU usage for the `cfprefsd` process. I’ve never been able to reproduce this issue so it’s been hard for me to diagnose, but thanks to some helpful people I’ve been told it seems to happen when MacID is searching for your device to connect to.

Unfortunately this means that this is an issue internally where the system is accessing the Bluetooth plist file, and there’s not much I can do about that. If I stop MacID from scanning, then of course MacID would never connect to your device and it would be useless.

Thankfully this doesn’t happen to everyone, but if you are affected the more information you can provide about when it happens will help me narrow the issue down and file a decent bug report with Apple. What would be even more helpful is if you can send me a Bluetooth diagnostics report, along with your model of Mac and the version of OS X you’re using.

Here’s how to start a Bluetooth diagnostics report:

  • When the issue has happened, hold alt/option and click the Bluetooth icon in the menu bar
  • From the menu that appears choose “Create Diagnostics Report on the Desktop…”
  • After a moment a zip file will appear on your desktop, forward that file to the feedback email address and I’ll add it to the bug report with Apple

Any help you can provide will go a long way to getting this issue fixed. I can’t file a bug report with Apple until I can either reproduce the issue or forward on a report from someone who has. Thanks!

11 thoughts on “High cfprefsd CPU usage when using MacID”

  1. Hello ! I’ve installed the last OS X update (10.11.5), and the problem has gone. The CPU usage of cfprefsd is back to normal for now.

  2. Another note:
    Just had an occurrence of this and I did an:
    killall cfprefsd
    Once it restarted, the high CPU returned
    I then Killed and restarted MacID and now cfprefsd is again using normal (nominal) CPU.
    macid@kendallspace.net

  3. Any progress on this issue? I’ve sent you the diag report. This is getting quite annoying having to shut down macid all the time…

  4. I though something was wrong with Skype–typing was stuttering, often lagging 3-4 keys behind.

    Activity Monitor showed cfprefsd sucking up all of my CPU.

    I then came across this post, quite MacID, and now Skype is lag-free and cfprefsd stopped being the CPU succubus.

    Unfortunately, MacID lost. I am not relaunching it until it’s fixed.

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