25 Jul
2014
25 Jul
'14
12:05 p.m.
I've just done some quick testing of AVLinux vs. Ubuntustudio, and the
performance of jackd is significantly worse on ubuntustudio..
On AVLinux, I can start up jack (0.121.3) with 32 frames, and CPU runs
around 3%. On Ubuntu (jackd 1.9.10), I am getting 30%+ with the same
settings.
Checking top, I am getting pulseaudio at 30% and jackdbus at 20%..
Killing pulseaudio, jackdbus goes down to 13%, but this is still
significantly worse than avlinux..
I'm wondering if it is due to differences in new vs. old jack, or if
there is something else I can tweak?
James
25 Jul
25 Jul
1:20 p.m.
Ah - just tried uninstalling jack and reinstalling, and jackd2 now
seems to work pretty much as expected. Seems I had a few kxstudio
jackd libs knocking around that seemed to be interacting badly with
the default ubuntu stuff..
On Fri, Jul 25, 2014 at 11:05 AM, James Stone <jamesmstone(a)gmail.com> wrote:
I've just done some quick testing of AVLinux vs.
Ubuntustudio, and the
performance of jackd is significantly worse on ubuntustudio..
On AVLinux, I can start up jack (0.121.3) with 32 frames, and CPU runs
around 3%. On Ubuntu (jackd 1.9.10), I am getting 30%+ with the same
settings.
Checking top, I am getting pulseaudio at 30% and jackdbus at 20%..
Killing pulseaudio, jackdbus goes down to 13%, but this is still
significantly worse than avlinux..
I'm wondering if it is due to differences in new vs. old jack, or if
there is something else I can tweak?
James
3:30 p.m.
On Fri, 25 Jul 2014, James Stone wrote:
Ah - just tried uninstalling jack and reinstalling,
and jackd2 now
seems to work pretty much as expected. Seems I had a few kxstudio
jackd libs knocking around that seemed to be interacting badly with
the default ubuntu stuff..
Running ubuntustudio 14.04 here. jackdbus is set 2/32 and I turned
pulse->jack bridging on. qjackctl shows DSP at 6-12%, Gnome system monitor
shows all cores at around 4%, Top shows pulse at 11%, the sound card at
6%, jack at 3.5%, a2jmidid at 2%.... turning pulse off has top showing the
sound card at 8%, jack at 6% and a2j at 2%, but jack DSP is 3.5%. All of
which brings into question the tools we use for measuring this stuff and
what those numbers really mean.
Setting my system to desktop mode (2048 frames, pulse on) gives jack dsp
of .88% (or less) and makes them harder to follow in top because they are
now at least fifth down and all less than 1%.
--
Len Ovens
www.ovenwerks.net
26 Jul
26 Jul
12:27 a.m.
On Fri, 25 Jul 2014 06:27:54 -0700 (PDT)
Len Ovens <len(a)ovenwerks.net> wrote:
Running ubuntustudio 14.04 here. jackdbus is set 2/32
and I turned
pulse->jack bridging on. qjackctl shows DSP at 6-12%, Gnome system
monitor shows all cores at around 4%, Top shows pulse at 11%, the
sound card at 6%, jack at 3.5%, a2jmidid at 2%.... turning pulse off
has top showing the sound card at 8%, jack at 6% and a2j at 2%, but
jack DSP is 3.5%. All of which brings into question the tools we use
for measuring this stuff and what those numbers really mean.
Setting my system to desktop mode (2048 frames, pulse on) gives jack
dsp of .88% (or less) and makes them harder to follow in top because
they are now at least fifth down and all less than 1%.
You are comparing apples and oranges :)
Most of those measurements are cpu use, qjackctl's dsp load is a
measure of latency (execution time). That is to say there is a deadline
given by the sample rate divided by the buffer size. If DSP load is
50%, the audio processing has used up half of the time available. If
100% it has used up all the time. Note that there is overhead
involved, the conventional wisdom is to not go over 50%, but ymmw..
--
Joakim
2:22 a.m.
On Sat, 26 Jul 2014, Joakim Hernberg wrote:
On Fri, 25 Jul 2014 06:27:54 -0700 (PDT)
Len Ovens <len(a)ovenwerks.net> wrote:
I think that was my point. Except I was also pointing out that looking at
cpu usage is not the greatest number to use because every program that
shows it seems to say something different, so knowing what that number is
made up of is important. Probably DSP load gives the best idea of what is
left in the system for audio. CPU usage does not take into acount that
some things that jack does are all on one thread/core.
--
Len Ovens
www.ovenwerks.net
Running ubuntustudio 14.04 here. jackdbus is set
2/32 and I turned
pulse->jack bridging on. qjackctl shows DSP at 6-12%, Gnome system
monitor shows all cores at around 4%, Top shows pulse at 11%, the
sound card at 6%, jack at 3.5%, a2jmidid at 2%.... turning pulse off
has top showing the sound card at 8%, jack at 6% and a2j at 2%, but
jack DSP is 3.5%. All of which brings into question the tools we use
for measuring this stuff and what those numbers really mean.
Setting my system to desktop mode (2048 frames, pulse on) gives jack
dsp of .88% (or less) and makes them harder to follow in top because
they are now at least fifth down and all less than 1%.
You are comparing apples and oranges :)
Most of those measurements are cpu use, qjackctl's dsp load is a
measure of latency (execution time). That is to say there is a deadline
given by the sample rate divided by the buffer size. If DSP load is
50%, the audio processing has used up half of the time available. If
100% it has used up all the time. Note that there is overhead
involved, the conventional wisdom is to not go over 50%, but ymmw..
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days inactive
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4 comments
3 participants
participants (3)
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Joakim Hernberg -
Len Ovens