Roon using using excessive CPU resources

Mac mini 2018, 3.2Ghz Intel Core i7, 16GB 2667 MHz DDR4
macOS Mojave version 10.14.4
Roon version 16 (build 416) stabile (64bit)

I’m running a Roon core on a Mac mini, but it constantly uses excessive CPU, with the fan going full blast all the time to keep it cool. I have noticed that I constantly see a spinner in the top right hand of roon, despite having “Adding Music to Library: Complete”

When you open a support topic there were many other things requested about your setup…this helps us help you.

How big is your library and how do you connect to it?

Is it still being analyzed? See under settings / library if any activity is there and also screen shot please of how many cores are being used or if it’s set to throttled.

At the moment I only have 283 tracks imported

And the tracks are all in the media folder on the same computer

Any tracks in skipped files?

I’ve seen some systems struggle with some possibly corrupt files and the logs normally help support guys isolate what’s gone off the rails.

They (support) should drop a post in here in due course. Hang in there.

I actually have the same problem, but only since build 416. Before that, no CPU problem. Now, the fans come on almost immediately, 360% CPU usage… (i9 CPU, iMac 2019 talking to a NUC running ROCK).

Just for kicks, re-downloaded the Mac OS X executable, still 360% but now split into Roon 260%, and RAATServer 100%.

Have just deleted and reloaded for the second time and suddenly everything is working with only 7% CPU usage.

Wish I’d be so lucky. Re-downloaded the Roon full package for Mac OS X again, and copied the Roon app to /Applications. No change - still 360% CPU usage…

What is wrong here? Same download runs fine on a MacBook Pro…

Hmm, just updated to Mojave 10.14.5, and the excessive CPU usage issue seems to be gone. 3x re-installation from the Roon DMG file did NOT accomplish this…

Hi @Andrew_Sykes & @Paul_Bemelmans,

Apologies for the delayed response here, I brought up this thread with the team today and I wanted to take a closer look at what may have been happening here. I have a few questions to clarify a few aspects:

  • Do you by any chance recall how long Roon was in this state for?
  • Did you try rebooting the Mac and was the behavior the same after the reboot?
  • Were there any other issues during this period of high CPU usage such as dropouts, slow Roon loading behavior, ect?
  • After reinstalling the App a second time, did you start fresh or restore from one of your Roon backups?
  • Can you please let me know what OS version you were using before updating to Mojave?
  • Were you by any chance seeing an activity spinner in the top right-hand corner like Andrew or was this absent?
  • Are you making use of a NAS or any other network storage paths?
  • Was the iMac rebooted after re-installing the app?
  • Were there any other issues during this period of high CPU usage such as dropouts, slow Roon loading behavior, ect?
  • Did you use the same Roon library after the OSX upgrade or did you start with a fresh database?


Hi @noris

Actually, the only thing I noticed on my quite-powerful i9-CPU equipped iMac is that the fans came on a little while after starting the Roon application. (Only used for controller purposes; Roon Core is running elsewhere on a NUC.)

  • The OS version before was also Mojave, 10.14.4.
  • No spinners or anything, and responsiveness was still good.
  • I’m using two NAS paths: one on a Synology 1512+, and one on the very same iMac. Local disk on the iMac, but a network path on the NUC of course.
  • So, no performance issues really, nothing noticeable except for the 360% CPU usage and the fans coming on - which is a bit disturbing, of course.
  • Same library was used. Only thing I did is drop build 416 on top of the old one in /Applications. And meanwhile, on a MacBook pro, running the very same OS the CPU problem did not materialise. And, is now gone with Mojave 10.14.5…


With hindsight I think the spinning wheel occurred because I asked roon to catalogue my entire computer rather than the music folder. When I realised and changed to the music folder only the spinning soon stopped, but the CPU usage was still high.
On the first reboot the problem was still there, but it resolved after a third reboot and reinstall.
There were no unusual issues other than the high CPU usage.
I started from fresh.

3 posts were split to a new topic: Roon on iMac High CPU Usage

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