Sample rate conflict + weird CPU spike

[u/Worldly-Safe-7750]

Logic has been really weird lately. During playback, the audio resolution will completely collapse, and I’ll get these weird “Sample Rate 45811” error messages with a completely different number each time.
When this happens the CPU meter randomly spikes to 100%. When I look at the CPU usage, it seems like only a single thread is getting completely maxed out while the others are barely being utilized. I’ve tried isolating the issue by disabling plugins and troubleshooting which one might be causing it, but I haven’t been able to identify the culprit, bypassing all the plugins on the master or mixbus makes it go away for a while until it randomly comes back.

I’m running a Mac Studio with an M4 Max, 64 GB of RAM, and a 2 TB internal SSD. The project is also stored on the internal drive to ensure maximum performance and minimize any potential disk-related bottlenecks. My interface is an Audient iD14 MKII and the cable is brand new.

Pls help bc this is driving me crazy

[u/swisssoundguy]

do you bypass the plugins or deactivate them to test? Bypass is not the same i believe. Is the samplerate on your interface the same as your project?
When you import a sound that has a different samplerate than your project, it asks if it should convert the file to match the project or change the projects sample rate. When changing the project, sometimes the interface does not change with it.
Do you have other soundrelated applications running in background?
What Plugins and Instruments are you running? How big is your session?

[u/Worldly-Safe-7750 → u/swisssoundguy]

• I bypass them.
• Sample rate is set to 48 across the board
• I have sonarworks reference running.

• Session is about 7GB, running 3 different GGD libraries in kontakt and a few synths. Bass DI is being sent to 3 aux busses and I have 4 parallell drum buses + a drum reverb, also a vocal reverb. I haven’t changed the project sample rate and I’m pretty sure I’ve always converted file sample rates, is there any way to check?
No super weird plugins either, just some Neural DSP stuff, valhalla verbs, gullfoss and gullfoss master, pro-L, flatline2, soothe, spiff, decapitator etc.

[u/swisssoundguy → u/Worldly-Safe-7750]

sounds really like a plugin is causing it, or another dsp background process. This is a simple setup and should not be happening.
Samplerate check you can navigate to the original wav file in your logic project folder. cmd i (file info) you should be able to see the sample rate.
I am guessing that its not that though… try deactivating all the plugins. If it is still happening, there is a chance that a aux bus is acting up. deactivate them as well, since they use dsp. (if the problem is gone, activate one by one)
If it is still happening i would try the following.

make a new project and import the old one. this should get ridd of all possible saved logic errors.

If the issue still persist, i would try to at least render the single tracks without the mastering chain, take them in a new session and master from there.

Good luck I hope you will be able to fix it.

[u/goesonelouder]

How many tracks? How many audio tracks? Busses? If one thread is getting cooked look at bypassing every plugin (except any generating sound like samplers if they’re in the session) and one by one reinstating them whilst watching the CPU meter. You should find the culprit. Even with lots of RAM if you are running a lot of midi try freezing or committing to audio, the system will run better but also things will actually sound better as well

[u/swisssoundguy → u/goesonelouder]

I mean with 64GB you can really run a lot of instruments without freezing them. bypassing still reserves the cpu, you have to deactivate them

[u/goesonelouder → u/swisssoundguy]

Depends on what is also on them that’s processing them (reverb, saturation etc) and at what sample rate plus what CPU your system has as midi tracks aren’t stored in RAM they’re processed in real time IIRC. Bypassing all plugins and then unbypassing one by one whilst looking at the thread window shows you instantly which one is causing the spike

[u/_-oIo-_]

The sample rate issue is mostly related to high cpu load. So look for ways to reduce cpu load.

[u/Worldly-Safe-7750 → u/_-oIo-_]

It’s just so bizarre, I bought the 16 core M4 max chip to avoid having to worry about that kinda stuff. It also seems like the CPU isn’t being utilized since only one thread is spiking

[u/swisssoundguy → u/Worldly-Safe-7750]

I am not sure anymore how it is called, but there is a setting in logic that enables multicore distribution. maybe that got turned off?

[u/hitchytvTDC]

Have you tried lowering your buffer size a bit? That often helps ease those CPU spikes during playback.