[solved] XRUN every ~110 seconds with USB audio interface

[Baggypants]

Can you test -r 48000 with and without -S? It might be the thing about usb interfaces not liking fractional latencies.

Is it possible to improve CPU and I/O scheduling

Here we go. It’s more important for the Jack period / buffer settings to set up whole integer latencies for usb devices, e.g. 10ms rather than 10.33333 ms, having 2 or 3 periods is pretty irrelevent. https://wiki.linuxaudio.org/wiki/list_of_jack_frame_period_settings_ideal_for_usb_interface improvements in kernel 5.16 Linux 5.16 Aims For Better USB Low-Latency Audio Playback - Phoronix