> Notes.log/.sh/.env
jackd 1.9.22 cold-boot xrun trace
$ uname -srm
Linux 6.8.0-31-lowlatency x86_64
$ jackd -R -P95 -dalsa -dhw:RME -r48000 -p128 -n2
jackdmp 1.9.22
Copyright 2001-2005 Paul Davis...
JACK server starting in realtime mode with priority 95
self-connect-mode is "Don't restrict self connect requests"
audio_reservation_init
Acquire audio card Audio0
creating alsa driver ... hw:RME|hw:RME|128|2|48000|0|0|nomon|swmeter|-|32bit
control device hw:0
configuring for 48000Hz, period = 128 frames (2.7 ms), buffer = 2 periods
ALSA: final selected sample format for capture: 32bit integer little-endian
ALSA: use 2 periods for capture
**** alsa_pcm: xrun of at least 1.482 msecs
**** alsa_pcm: xrun of at least 0.041 msecs
**** alsa_pcm: xrun of at least 0.118 msecs
# always on first ~6s after cold boot. never after warm reboot.
# suspected: PCIe ASPM L1 entry while RME card is idle pre-stream.
$ sudo cat /sys/module/pcie_aspm/parameters/policy
[default] performance powersave powersupersave
$ sudo bash -c 'echo performance > /sys/module/pcie_aspm/parameters/policy'
$ sudo systemctl restart jackd
# cold boot xruns: 0 over 24h.
# idle power draw: +4.8W. acceptable.