27 Jul
2019
27 Jul
'19
11 p.m.
Am 28.07.19 um 04:05 schrieb liebrecht(a)grossmann-venter.com:
Anyone have an in depth treatise on xruns and how to minimize them. By
that I dont mean just adjusting the buffer size, I mean really getting
into the gears of why xruns happen and how to potentially minimize them.
Reason I ask is that I use jack on a live music basis amd it is
crucial for me to get no more than 2.9ms latency.
I can hear and feel every latency above above that.
I am lucky with mixbus and jack on Linux to get 2.9ms with the
occasional xrun every 2 minutes, but I want to see if I cannot
eliminate them.
Any advice or point to very relevant reference material will be
appreciated.
Thanks
What I found over the years is, there is no general rule for how to
optimize your system. It depend deeply on your hardware.
I could say what I need to do with my current machine, beside the usual
tweaks.
First I use a rt-kernel, then I add the following kernel parameters:
threadirqs intel_pstate=disable processor.max_cstate=1
intel_idle.max_cstate=0 idle=poll
only with them I'm able to run smooth at low latency.
This is with a Quad Core model: Intel Core i5-7400 CPU.
Additional, when I need full power, I increase the priority for my
sound-card thread, therefor I run as root:
chrt -f -p 95 $(ps -eLo pid,cmd | grep -i snd_hda] |sed q| cut -d' ' -f3)
were snd_hda is m sound-card.
All this wasn't needed with my previous PC.
regards
hermann