On Thu, 2006-06-01 at 08:52 +0200, Clemens Ladisch wrote: > Matthieu Redouin wrote: > > I am trying to have short latency on my computer. I am using the > > hda-intel driver and I am wondering about the output latency : > > - with a buffer size of 64 and period of 2, I get around 1.5ms of output > > latency > > - with a buffer size of 64 and period of 4, I get around 4.2ms of output > > latency ! I don't figure out this big difference. > > What are the units you're using here? Is your period size in bytes, in > frames, or the number of period per buffer? And what are the sample > format and rate? sorry, I am using frames for the buffer size and for the period, it is the number of period per buffer. The sample format is 32bit LE and the rate is 48000Hz (and 2 channels).
> > Setting period size to 4 allows me to set buffer size to 16 and have an > > output latency of 1.2ms, whereas period size of 2 and buffer size of 16 > > gives me too many xruns (even with patched kernel). > > So I am wondering if buff/period size of 64/2 was my hardware limits and > > 16/4 settings only a trick handled by the driver ? > > Have a look into /proc/asound/card0/pcm0p/sub0/hw_params to see what the > parameters used by the driver are. thanks !!! It helped a lot. So in fact, my problem is not really about buffer size, but xruns : - when I start Jack with -p16 (period size in frames) -n4 (number of period), I get no xruns - when I start with -p32 -n2, I have a lot ! why ? shouldn't it be the same thing ? And my kernel is already patched. thanks for the tips, matt _______________________________________________ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
