[Ardour-Dev] Recording may channels at once
Kjetil S. Matheussen
k.s.matheussen at notam02.no
Fri Jul 4 04:05:21 PDT 2008
On Fri, 4 Jul 2008, Sampo Savolainen wrote:
> On Thu, 2008-07-03 at 16:25 +0200, Kjetil S. Matheussen wrote:
> > (cc to ardour-dev)
> > On Wed, 2 Jul 2008, Thomas Vecchione wrote:
> > >
> > >
> > > And is far from a standard setup as well;) If the OS is running from
> > > memory, and you are not swapping anything in or out of the swap partition(Or
> > > file as the case may be), but are still running X, GUI based programs(Azerus
> > > etc.) and doing 128 tracks of recording, all from a single disk, you are
> > > pretty lucky IMO, even on Linux. I can't even depend on 64 tracks without a
> > > dropout due to disk access on a system disk. 32 is even pushing it, but i
> > > will say I have done it. This is running Ardour, X, e17, jackd, and that is
> > > about it, on a properly patched kernel, with proper PAM permissions, but
> > > that does still have logging set up etc.
> > >
> > I think this might be because ardour records to separate files. I just
> > tried recording 128 channels in ardour using 16 X 8 channel tracks,
> > and it failed quite immediate. Recording 128 channels using jack_capture,
> > on the other hand, seems rock solid. Recording 64 channels (8 X 8) in
> > ardour seems to work fine too.
> Your CPU might be running out of time, or your disk system (platters or
> filesystem or memory).
> > However, it could also be because Ardour does some graphical operations
> > while recording. Is there any way to turn off all that?
> You can disable showing waveforms while recording (View->show waveforms
> while recording). You used to be able to disable the "pink boxes" also,
> but I can't find the option in 2.0 ongoing at the moment. But ...
I just did some benchmarks recording 128 channels (16 X 8):
Recording times before failing, without waveforms while recording:
Recording times before failing, with waveforms while recording:
I run some other programs in the background accessing the
disk, so that could explain the large variations.
However, recording times before failing, using jack_capture,
128 channels, 5 second buffer, "$jack_capture -dm -B 5 -c 128" :
Manually stopped after 7.59 minutes, no failure.
> > Perhaps this is an area where Ardour could be optimized quite a bit?
> .. If jack (and thus, the Ardour audio thread) is running with realtime
> scheduling plus you have a sane kernel and enough memory - none of these
> things really matter. The audio and disk threads will always get
> priority over the GUI and thus no pink box will interfere with the
> performance that really matters.
Yes, but jack_capture only writes to one file, while ardour
writes to several. That could explain the difference.
> Oh, and proper scheduling also promises food for everyone and world
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