Hi all. There was a thread about sound performance recently on the Linux Audio User mailing list. It seems that a recent kernel (2.6.24, even the realtime patched variety) has performance issues. I too have noticed degradation in audio performance since upgrading to Ubuntu 8.04 (in fact, there have been quite few other issues that came with the new upgrade, not necessarily audio related). I have to boot into an older kernel (2.6.20-16--realtime) for decent audio. ./MiS On Sat, Oct 25, 2008 at 1:14 AM, Hector Centeno wrote: > Also if you used Jack instead of Alsa you could expect to get much > better latency. Is there any reason why you are not using Jack? Also I > recommend you to try to get the RT kernel running. Are you > experiencing hard locks when using it? (but this might be topic for a > different list). > > Cheers, > > Hector > > > On Fri, Oct 24, 2008 at 6:50 PM, Tobiah wrote: >> Hi, it's been a while! >> >> I've been off csound for at least a year, probably more. >> It's always on my mind though, and circumstances permit >> that I am able to delve back in for a while. >> >> I remember getting rather astonishingly low latency controlling >> csound from my midi keyboard in the past. I've made a new simple example, >> and >> am finding that I have to set buffer sizes to around 8192 samples >> to avoid buffer underruns! Needless to say, this is too slow >> for keyboard playing. >> >> I'm on a fairly quick machine, running kubuntu 8.04. I tried >> installing the realtime kernel, but there doesn't seem to be >> any benefit from booting it, and it invariably crashes after a while. >> >> Can anyone see what I might be missing, or suggest any tweaks >> to try? Under the below example, I get constant >> "WARNING: Buffer underrun in real-time audio output" >> They don't go away until I use huge buffer values. >> >> I've achieved beautiful results on this box previously, >> but with a different installation. >> Thanks, >> >> Toby >> >> The soundcard is an echo Mia MIDI. >> >> **Csound version 5.08 (double samples) Apr 16 2008 >> >> **CPU: Intel(R) Core(TM)2 CPU @ 1.86GHz >> >> **Command line: >> >> sudo csound\ >> -+rtaudio=alsa\ >> -+rtmidi=alsa\ >> -o dac\ >> -d\ >> --midi-device=hw:0,0\ >> -B 512 -b 256 --sched\ >> --midi-key-cps=5\ >> --midi-velocity-amp=4\ >> orc sco >> >> **Orchestra: >> >> sr = 44100 >> ksmps = 100 >> nchnls = 2 >> >> instr 1 >> >> aPitch init p5 * .5 >> >> asigl oscil p4, aPitch, 1 >> asigr oscil p4, aPitch + 1, 1 >> outs asigl, asigr >> >> endin >> >> >> **Score: >> >> f1 0 65536 10 1 .5 .25 .125 >> f2 3600 >> >> >> >> >> Send bugs reports to this list. >> To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe >> csound" >> > > > Send bugs reports to this list. > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe csound" > -- ./MiS 514-344-0726 http://www.creazone.ca