30 Jan
2004
30 Jan
'04
9:45 p.m.
Hi
It seems that I get quite stable performance by starting jack like this
on my P4 2.4Ghz laptop with onboard i810:
jackstart -R -v -d alsa -n 3 -p 256 -zt
But what exactly does this translate to in terms of latency? Should I
expect more? I get almost the same performance under 2.4.23 with Andrew
Morton's low-latency patched and 2.6.2 with or without the mm-patch.
--
peace, love & harmony
Atte
http://www.atte.dk
30 Jan
30 Jan
10:09 p.m.
Atte André Jensen <atte(a)ballbreaker.dk> writes:
It seems that I get quite stable performance by
starting jack like
this on my P4 2.4Ghz laptop with onboard i810:
jackstart -R -v -d alsa -n 3 -p 256 -zt
But what exactly does this translate to in terms of latency?
Divide frame counts by (frames/second) to get seconds.
Your input latency is 256/48000, 5.333 milliseconds. The output
latency is three times that because of -n3, 16 msec. This is the
latency due to buffering between the device and JACK. Clients may
introduce additional latency depending on the processing they perform.
Well-behaved clients should report this extra latency for each of
their output ports. There will also be some small but unknown
hardware latency due to the A/D and D/A converters.
Should I expect more?
I don't know. Depends on many system-level hardware and software
performance and configuration options.
I get almost the same performance under 2.4.23 with
Andrew Morton's
low-latency patched and 2.6.2 with or without the mm-patch.
That's probably pretty good then, though there are other things to
tune besides the kernel.
--
joq
10:54 p.m.
On Saturday 31 January 2004 1:41 am, Atte André Jensen wrote:
Hi
It seems that I get quite stable performance by starting jack like this
on my P4 2.4Ghz laptop with onboard i810:
jackstart -R -v -d alsa -n 3 -p 256 -zt
But what exactly does this translate to in terms of latency?
I get about 10mS delay at that setting, I have a slower CPU, but I don't know
if that makes any difference.
Should I
expect more? I get almost the same performance under 2.4.23 with Andrew
Morton's low-latency patched and 2.6.2 with or without the mm-patch.
probably not then. I think this is about right for an i810 - it's useable.
cheers
tim hall
31 Jan
31 Jan
6:04 p.m.
FWIW,
I'm obsessed with getting lowlatency (don't ask why). I have a Dell
5100 3.2ghz p4, 640 mb ram with a built in i810.
I reliably run jack with
-p 128 -n 3 -r 48000
giving about 8ms latency and few xruns.
-ry
On Sat, 2004-01-31 at 02:41 +0100, Atte André Jensen wrote:
Hi
It seems that I get quite stable performance by starting jack like this
on my P4 2.4Ghz laptop with onboard i810:
jackstart -R -v -d alsa -n 3 -p 256 -zt
But what exactly does this translate to in terms of latency? Should I
expect more? I get almost the same performance under 2.4.23 with Andrew
Morton's low-latency patched and 2.6.2 with or without the mm-patch.
--
peace, love & harmony
Atte
http://www.atte.dk
3 Feb
3 Feb
6:20 p.m.
Ryan wrote:
I'm obsessed with getting lowlatency (don't
ask why). I have a Dell
5100 3.2ghz p4, 640 mb ram with a built in i810.
I reliably run jack with
-p 128 -n 3 -r 48000
giving about 8ms latency and few xruns.
What do you use to measure latency? I've tried a few utilities that I found
linked from some of the audio sites, but they were all pretty old and all of
them wouldn't compile/run for some reason or other.
Thanks,
Anthony
http://nodivisions.com/
7389
days inactive
7393
days old
linux-audio-user@lists.linuxaudio.org
4 comments
5 participants
participants (5)
-
Anthony DiSante -
Atte André Jensen -
Jack O'Quin -
Ryan -
tim hall