[Ardour-Dev] Recording may channels at once

[Kjetil S. Matheussen]

On Thu, 10 Jul 2008, Kjetil S. Matheussen wrote:

> 
> 
> On Wed, 9 Jul 2008, Sampo Savolainen wrote:
> 
> > On Fri, 2008-07-04 at 13:05 +0200, Kjetil S. Matheussen wrote:
> >> I just did some benchmarks recording 128 channels (16 X 8):
> >>
> >> Recording times before failing, without waveforms while recording:
> >> 55s
> >> 19s
> >> 8s
> >>
> >> Recording times before failing, with waveforms while recording:
> >> 16s
> >> 24s
> >> 18s
> >>
> >> I run some other programs in the background accessing the
> >> disk, so that could explain the large variations.
> >
> > Sounds bad though. Can you try the same test so that you use the same
> > background load. Preferably no extra load.
> >
> 
> It's a bit more consistent now. Below are results without any other
> programs running, exept emacs, pine, jack, konsole and qjackctl.
> I had 1GB free of memory, and had 5.94s long buffer for ardour.
> Total CPU usage was, according to "top", about 20% while recording,
> and Jack reported about 12% dsp cpu usage.
> 
> 09s
> 13s
> 12s
> 12s
> 12s
> 19s
> 
> The next time I tried, after the result with 19 seconds, something 
> interesting happened. Suddenly, after a few seconds, I get a bunch of 
> errors which says something like this:
> 
>    "can not write peak file, too many open files",
> 
> and when I press the stop button, ardour crashes.
> 
> I would think this is an OS limitation (although one not very gracefully
> handled by Ardour), but anyway, if ardour writes peak files while 
> recording, then it's not that strange that jack_capture performs so much 
> better.
> 
> I guess I got the error because this was the 7th recording, with
> 128 peak files, yielding about 128*7 files.
> This is how I worked:
> 
> 1. Record.
> 2. Write down how many seconds of sound recorded.
> 3. Undo Capture
> 4. Goto 1.
> 
> Why isn't the older peak files closed and deleted?
> 
> kjetil at ttleush ~/longrecording/peaks $ ls -la |wc
>      874    8730   57091
> kjetil at ttleush ~/longrecording/peaks $
> 
> 

Oh, and the audio files weren't deleted either between each
capture:

kjetil at ttleush ~/longrecording $ ls -la interchange/longrecording/audiofiles/ |wc
    907    9060   57457
kjetil at ttleush ~/longrecording $