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Comment by viraptor | Hacker News Reader

> and I have no idea what the culprit might be.

I'd start with checking all sinks/sources to make sure you're not resampling by accident. But even that shouldn't be causing high CPU by itself. There's pw-top/pw-profiler to help you.

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Thanks for the pw-profiler recommendation, wasn't aware of that one.

I believe the Pro Audio profile [0] (which I'm using) doesn't resample by default.

Using pw-top, I noticed that something was causing xruns [1] (see ERR column) though I was unsure what that was. Since the Pro Audio profile uses the IRQ mechanism, I looked at interrupts [2] but couldn't spot anything unusual. There is however irq/16-mmc0 process which is at times causing significant (>50%) CPU usage, so I think I need to unload the sdcard module and see if that fixes anything.

First however I think I'll try a newer kernel (linux-lowlatency-hwe-22.04, which according to apt search is on 6.2.0.1017.17~22.04.14 as opposed to the current 5.15.0-89-lowlatency that ships with Ubuntu 22.04)

0: https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/FAQ...

1: https://paste.debian.net/1298908/

2: https://paste.debian.net/1298905/

When reading posts like these, I sometimes I feel very lucky having a MacOS M1 setup that does what it's supposed to and which works almost seamlessly with external hardware. Best of luck to your venture.

I think that's skipping some context though. Don't know about the previous poster, but I'm using pipewire for things that MacOS just can't do, at latencies which MacOS can't pull off, with codecs that MacOS can't support. So although I spent an hour or so on the setup / resolving issues, that's still 100% better.

Yeah, the basic things just work on MacOS. But try to do fancy audio routing, low latency processing and other things and you're left with spending hundreds of dollars on apps that give you half a hacky solution.

I'm sure PipeWire is technically more advanced, but as someone that just wants to make music using a DAW by tracking external synthesizers, a _bit_ higher latency doesn't kill, especially if the DAW can compensate for said latencies.

It's nice to hear that PipeWire supports more codecs, but here WAV, FLAC and MP3 are more than sufficient for my needs (and the needs of 99% of producers out there)

At the end of the day when I'm inspired I simply want to make music instead of mucking around with config and troubleshooting. It might be that the Linux audio landscape will offer this at some point, but I don't see that happening any time soon.

> Yeah, the basic things just work on MacOS. But try to do fancy audio routing, low latency processing and other things and you're left with spending hundreds of dollars on apps that give you half a hacky solution.

This; and that also includes running macOS version a release, two or three behind, because the newer ones break your setup.

> This; and that also includes running macOS version a release, two or three behind, because the newer ones break your setup.

That's true, and it's a widely known wisdom, but in my case my Mac isn't even connected to the network: I'm using it just as an appliance solely dedicated for audio / video editing and production.

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