[PlanetCCRMA] Best performance?

Mark Knecht Mark Knecht <markknecht@gmail.com>
Tue Nov 16 07:44:01 2004

Be careful if you try this. My system was completely stable for 3
minutes with 25 tracks and with the option to run plugins while
recording turned off. However, with the option turned on the machine
failed with a hard hang (power switch type) after about 30 seconds of
recording. fsck on reboot is complaining about Ardour audio tracks
being corrupted.

- Mark

On Tue, 16 Nov 2004 07:10:36 -0800, Mark Knecht <markknecht@gmail.com> wrote:
> On Tue, 16 Nov 2004 22:24:10 +0800, Timo Sivula <timo.sivula@luukku.com> wrote:
> > Dear Jack, Linux and Planet CCRMA addicts,
> >
> > I propose a contest of who can run his or her home studio in realtime
> > with a latency less than 10 ms for the longest consecutive time without
> > a single xrun. Minimum software running has to be Rosegarden and Qsynth
> > with at least one soundfont.
> >
> > My system generates a couple of xruns at 4 am every night, but stays
> > stable for the rest of the day, so my record is 24 h with latency of
> > 8.71 ms.
> >
> > br, Timo
> There is a test we do in the Pro Tools LE forums that involves
> recording the largest number of tracks at the same time using plugins,
> the idea being to test both CPU power and disk access. Under Ardour
> something close would be done like this:
> Pretest setup - setup Jack for a specific known amount of latency,
> such as <10mS.
> 1) Set up a new Ardour session
> 2) Add a new track
> 3) Add to that track 5 plugins. (The Pro Tools tested used a strange
> set of plugins - one EQ - 3 different delays and a limiter. I would
> suggest choosing a more useful set, such as:
> a) All pass delay line, linear interpolation
> b) Auto phaser
> c) DJ EQ (mono)
> d) Multivoice Chorus
> e) SC1
> Enable all 5 plugins and record enable that track.
> 4) With this one track record enabled, enable Ardour to record and
> record audio from your sound card for 3 minutes without xruns. If you
> can't do that then back off on latency in Jack and try again until you
> find the most aggressive setting you can that will record xrun free
> for 3 minutes.
> 5) Noting DSP Load on the system duplicate the above 5-plugin track
> until DSP usage reaches but does not go above 80%. Ensure taht all
> tracks added are record enabled. While I haven't done it on my laptop
> this looks like it might be about 25 mono tracks.
> 6) When the multi-track test setup is complete (maximum number of
> tracks, all tracks have 5 identical sets of enabled plugins, DSP usage
> is not above 80%) then start recording and record for at least 3
> minutes without xruns.
> 7) If you cannot record for 3 minutes without xruns then remove tracks
> until you can.
> 8) Report the results - your CPU, system info, distro, disk speeds
> using hdparm -tT on your audio drive, Ardour and Jack revisions, etc.
> Beyond this Ardour/Jack only test I'd like to see a similar test done
> using VST plugins but I think it's 3-6 months early for that on a
> global basis.
> What do you think of this sort of test?
> - Mark