You don't need the realtime-lsm module any more. That has been superceded by rtlimits.
5ms sounds pretty good to me.. depends what card you are using. I get 20ms (512) for full duplex with SBLive! with no xruns, which is fine for my purposes.
If you really want to push the envelope with realtime, you need to install the realtime kernel patches,
but it is possible that your sound card might not be able to do this, unless it is a proper audiophile quality one..
James
On 12/20/06, J M Needham <J.M.Needham@xxxxxxxxxx> wrote:
Hi all,
So I've just installed Ubuntu 6.09, and followed the instructions on
http://fort2.xdas.com/~kor/oss2jack/install.html to install the
realtime-lsm module and I've added
@audio - rtprio 80
@audio - memlock 500000
to /etc/security/limits.conf and set the realtime mode on Jack. Seems ok,
the only thing is that I can't get below 5.8 ms latency. Jack's behaving
nicely with very few xruns, but won't do any better. The output of the
messages with 32 frames for capture, for example, is:
10:41:35.039 Startup script...
10:41:35.039 artsshell -q terminate
sound server terminated
10:41:35.375 Startup script terminated successfully.
10:41:35.381 JACK is starting...
10:41:35.382 /usr/bin/jackd -R -u -dalsa -dhw:0 -r44100 -p32 -n2 -S
10:41:35.391 JACK was started with PID=5503 (0x157f).
jackd 0.100.0
Copyright 2001-2005 Paul Davis and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
JACK compiled with System V SHM support.
loading driver ..
apparent rate = 44100
creating alsa driver ... hw:0|hw:0|32|2|44100|0|0|nomon|swmeter|-|16bit
control device hw:0
configuring for 44100Hz, period = 32 frames, buffer = 2 periods
ALSA: cannot set period size to 32 frames for capture
ALSA: cannot configure capture channel
cannot load driver module alsa
10:41:35.502 JACK was stopped successfully.
10:41:37.430 Could not connect to JACK server as client. Please check the
messages window for more info
And I can't see anything of any use in here. Any ideas?
Jonty
