I sent this mail a few days ago to debian-powerpc but had no reply. Maybe someone here will have an idea.
bye, Paul ----- Forwarded message from Paul Brossier <[EMAIL PROTECTED]> ----- Date: Sat, 14 May 2005 21:56:40 +0100 From: Paul Brossier <[EMAIL PROTECTED]> To: debian-powerpc@lists.debian.org Subject: alsa and jack latency Hi all, Trying to reduce the latency of jack on my ibook G4, i realised i can go down to 8.7ms using the oss mode, which is really good. But alsa won't accept running with less than 22ms and click on most X request: $ jackd -R -doss -r44100 -p128 -n3 -w16 works perfectly, 128*3/44100=8.7ms latency, hardly any xrun on heavy load $ jackd -R -doss -r44100 -p256 -n2 -w16 works fine, 11.6ms latency $ jackd -R -dalsa -r44100 -p128 -n3 -S runs but no clients can connect $ jackd -R -dalsa -r44100 -p256 -n2 -S fails saying ... ALSA: cannot set number of periods to 2 for capture ALSA: cannot configure capture channel $ jackd -R -dalsa -r44100 -p256 -n4 -S would run with 23.2ms latency, but xruns on most X queries It looks to me that this is related to the pmac driver. I have similar problems with snd-usb-audio and an edirol usb, which will only let jack run in oss mode. I wonder what prevents the pmac module to do so while the oss emulation layer does it very well. I am running 2.6.12-rc4, but had this problem with earlier 2.6 kernels. Any thoughts? Many thanks, Paul ----- End forwarded message ----- (mmh, pmac should really be powermac in the above) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
