On Wed, 21 Jan 2004 11:15:11 +0000 Steve Harris <S.W.Harris@xxxxxxxxxxxxxxx> wrote: > > I don't know what these numbers mean... > > > > What does this transalate to in interval-in-milliseconds, and after > > how many milliseconds delay will an underrun occur? > > The default sampe rate is 48kHz, so 1024 samples/block gives 21ms > between interupts. Jack easts a bit of that, but you'd have ~20ms > before an underrun occured. > > > And what else is happening on the system at the time? > > The original poster would have to anwer that. Jack itsself is just > messing with SYSV SHM and occasioanly touching fifos. > > As someone else said, jack runs reliably on most 2.4+ll+o(1)sched > systems with 5ms (256 sample) interupt fequencies and usually lower. I usually use 4 or 8 pretty large periods of 512 frames [my soundcard doesn't allow larger one]. On linux 2.4.22 [LL+preempt+cap patch] i can get very stable performance. I can even compile a kernel in the background and get no xruns [except for an occasional one]. I tested the 2.6.0 kernel and it was much more touchy. Start using the disk and xruns occur right and left. I will try the 2.6.1 today though.. I don't know though if i configured the 2.6 kernel right [preemptible, etc..] I once took a look at the latency measuring tools, but i could not really make sense out of them [not being a kernel hacker]. So i suppose testing would be much easier, if there was a little tool, which everyone could just run and it would do some testing which we could then report back to andrew.. Flo -- http://www.soundclick.com/bands/9/florianschmidt.htm http://www.arted.biz/mista.tapas
