[Ardour-Dev] Recording may channels at once

[Sampo Savolainen]

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 ...

> 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.

Oh, and proper scheduling also promises food for everyone and world
peace.

 Sampo