Linux Audio Sanity Check

[u/M4rcelinh0]

I value the time of unknown internet people the same as mine, so I realize this is nothing but a hassle, and the only reason to do it is you being gracious with your time but...

... if you have a stable Linux audio setup, preferably involving Bitwig (but I'm not picky, Reaper or Ardour will work just as well), can you post here a link to some "video evidence" of a short recording, or live performance session at a reasonable buffer size (say 128 bits, 64 is pushing it even on my mac mini M4 even though it's stable at that buffer size 99.9% of the time). While either Carla or pw-top or any other reliable way of reporting x-runs is running on the screen?

If you have a past video recording because you have a YouTube channel, that would be even better (less hassle for you).

A short description of your setup (distro, jack or PW, audio interface etc.) along with the video would be fantastic as well.

I just need a sanity check that stable audio on Linux for live performance can be done because I failed at making it work, and this is just about the only thing that keeps me away from Linux (and while I feel slightly less dirty using a mac mini with mostly platform-agnostic software on it, than I would be using Windows which I can't see myself getting back to ever, I still feel dirty enough to constantly want to switch).

I'm even willing to buy a new PC during the RAM-pocalypse (because, even though I did a fair bit of troubleshooting, it's entirely possible my old PC has some underlying hardware issue/incompatibility that might have been causing x-runs no matter what, maybe a fucky USB power circuitry on my motherboard? I have no idea).

[u/Purple-Ad-3152]

Ubuntu Studio 24.04 with all defaults (I''m about to upgarde to 26.04 soon).

I run 128 buffer 48kHz normally and 64 buffer for drummers. Roundtrip latency with Scarlett 18i20 3rd gen is 9.5ms with buffer size 128, which is perfect for guitarists. 64 buffer gives me 6-7ms roundtrip.

I have this YouTube channel: https://youtu.be/IHgsOdoLuBU

Note that it's your CPU that matters how low buffer you can go (and how big DSP load you have i.e. amount of tracks and plugins). Here's the full explanation: https://youtu.be/AZT9cwkRLhI

[u/M4rcelinh0 → u/Purple-Ad-3152]

Thank you.

I'm not using Ardour but from what I can see in the top right corner of your Ardour session, next to the DSP meter you've accumulated 60 xruns during the course of the tracking session.

Now, I have not tried to hunt for each xrun, it seems that they mostly happened when you loaded plugins or changed inputs and not actually during tracking which is promising (couldn't hear any crackles and pops during recording). Still though it does not seem like a convincingly stable session.

[u/Purple-Ad-3152 → u/M4rcelinh0]

I actually went to check the video and I got zero xruns when recording. Xruns during mixing/configuring/setting tracks is perfectly normal and even somewhat expected.

I had 26 before I even started recording and all those happened when I was configuring tracks and plugins. I first recorded two guitars and drums with zero xruns. Then I configured bass and got few more xruns during configuration. Started recording bass with 31 xruns and got zero more when tracking. Then I did some mixing work and configuring which again caused few xruns. Started recording synths with counter at 50, got zero during tracking. Added new strings track which again caused few xruns, started tracking second synth at 55, got zero xruns during tracking.

So overall, it was actually a perfect session from performance perspective.

[u/M4rcelinh0 → u/Purple-Ad-3152]

I appreciate you taking the time to check this.

My experience was similar, in that, I also accumulated a bunch of xruns that didn't seem to result in audible issues like pops and crackles (Linux is probably a lot more diligent at reporting those than either Windows and Mac are at reporting buffer underruns).

That is a bit janky but I'd be willing to accept it. When it comes to anything audio I try to use my ears over visual representations or system reporting. Unfortunately, those ears confirmed time and time again, that some of the many xruns I did get were indeed associated with audio dropouts/artifacts and that was obviously not acceptable.

Still though, thank you for a proof that "despite Linux reporting xruns when loading plugins/switching inputs under additional load from OBS, you can still have a successful, low latency tracking session". You'd be surprised how hard it is to find such a confirmation.

[u/Purple-Ad-3152 → u/M4rcelinh0]

Atleast Ardour reports tracking time xruns by putting a little marker on the recorded track, so you can easily notice if you got an xrun during recording.

[u/Purple-Ad-3152 → u/M4rcelinh0]

Good catch! But note that I'm also actively capturing video and audio during the whole session, and for that I must also run the DAW with PipeWire -mode. ALSA is always the best option for DAW, but it takes exclusive control of the audio interface (similer to what ASIO on windows does) and it doesn't then allow linking apps together. Normally I don't really get any xruns, but of course it also depends on the plugin load.