[linux-audio-dev] RE: [Jackit-devel] Re: k_jack v0.0.0.5

[Mark Knecht]

>
> Would you care to describe your setup, hardware/kernel versions etc...?
>
Robert,
   At the risk of looking like Steve's shadow, I run the PlanetCCRMA flow on
two machines. The low-end machine is an older Dell P3-500 with a Hammerfall
light and 768MB of DRAM. In that machine I run Jack with a -r 44100 -p 1024
setting, so latency is pretty high. (43mS?) It runs fluxbox and is
completely solid. I could probably lower the Jack latency settings but
haven't needed to you. I never see xruns.

   On my main box, where I run Ardour and Rosegarden, along with
fluid-synth, amSynth and a couple of other synths, I use an Asus A7V266-E
mobo with an Athlon XP 1600+ processor, 256MB DRAM, normal internal drives
and external 1394 drives using reiserfs. On that machine I normally run with
a -p 256 -n 2 setting, which I thin gets the latency down in the 10-11mS
range. I can run at -p 128, but down there I do see xruns too often.

   I have noticed that there are still a number of system oriented things
that, on my system, absolutely guarantee an xrun. The simplest is dropping
down to a console. (Alt-Ctl-F2) Normally I like to put Jack in it's own
console instead of running it on my desktop somewhere. With low settings (-p
256 and below) I see xruns coming from and going to console.

   I do not see xruns for other reasons, at least for the work model I have
right now, which is admittedly pretty simple. Possibly it will get worse
later. Typically I'm running 10-15 MIDI tracks in Rosegarden, sending them
to an external machine running GigaSampler, and bringing the audio back in
using Ardour. I never, ever see xruns when monitoring audio with Ardour. I
can create them if I try to record too many audio tracks at the same time. I
have not tried to optimize this yet, other than my recently published info
on xruns and file systems. (Thanks Jan!) I presume that there will always be
a limit to what any given system can do in terms of recording tracks, so I'm
not surprised to see this sort of limit in mine.

   WRT a previous comment about not using Jack at all, how would I use 5
soft synths, Ardour and Rosegarden at the same time without it, and only
using Alsa? Even if I didn't require low latency which I do) how would I do
that? I'm not clear?

Thanks,
Mark