Scsynth causes high coreaudiod idle load on macos

Hello, I have upgraded to Sonoma on an M1 MacBook Pro and noticed that whenever I boot the server the process coreaudiod is getting around 20% of CPU.

Any ideas?

Yes, I have the same (I’ve edited the title to make it clearer)

Since macOS 14 (Sonoma), miy impression is that the idle CPU load that scsynth (server) causes on coreaudio is higher than before. While scsynth runs with around 0.2 %, the measure for coreaudiod goes up to 15% once scsynth has started.

This is the same with the development branch and self-compiled version and older binary versions.

Maybe we can collect some experiences here.

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I am seeing Core Audio at ~15% on Big Sur 11.6 on 3-13-0-dev Intel i5

Sonoma 14.3, coreaudiod sits at 11% idling after server boot (SuperCollider 3.13.0)

macOS 14.5
M1 max
coreaudiod: 4.7%
scsynth: 0.9%
SC 3.14.0-dev

Performing a clean install of Sonoma resolved the issue for me. If I’m not mistaken, it seems there is no longer a coreaudiod process.

Not sure about this. The computer I use is brand new (was shipped with Sonoma) and I’m seing similar numbers. There might be another factor.

As an experiment, try using different sample rates from SC / use different sample rates from Audio MIDI Setup? I wonder if this is a case where SuperCollider is ended up running at a different rate than the device, and there’s sample rate conversion happening that’s causing the CPU load?

good idea! But this seems not to be the case.

  • OS: macOS 14.5
  • machine: m1max
  • SC3.14.0-dev

On Activity monitor:

  • coreaudiod % CPU: 14.24
  • scsynth % CPU: 0.61

On sclang

  • s.peakCPU
    → 0.1640625

  • s.avgCPU
    → 0.027599653229117

It’s really weird. I have crosschecked and there is no coreaudiod process at all on my M1 running Sonoma

As far as I have seen, MacOS above 12.6 has a problem with audio devices when waking from sleep.
Prior to 14.5, the most common phenomenon was that ALL audio devices would disappear.

The terminal command

sudo killall coreaudiod

was often useful. It can make the audio devices reappear. It did not always work, but it often worked well.

With 14.5, the audio devices have not disappeared, but they do not work.
Also, the terminal command

sudo killall coreaudiod

is less useful.

I do not know if this is relevant to this thread but share this…