[PlanetCCRMA] root vs capabilities

Fernando Pablo Lopez-Lezcano nando@ccrma.Stanford.EDU
Tue Jun 1 10:21:01 2004

> > If I understand capabilities, then in the context of
> > > my experience it's irrelevant what desktop I use (KDE)
> > > and what processes may be running as a result. Bottom
> > > line, everytime I attempt to work as a normal user I
> > > give up and run everything as su because xruns and
> > > disconnections from jack make it impossible to work.
> > 
> > How are you starting jack? What does it say when it
> > starts? As a normal user you should start it with the jackstart command
> > and the "-R" flag, like this:
> > 
> >   jackstart -R -d alsa -d hw
> > 
> > (with whatever parameters work with your card, of
> > course). 
> /usr/bin/jackstart -R -p512 -dalsa -dhw:0 -r44100
> -p256 -n2
> that's the .jackdrc file that qjackctl uses.

That sounds fine. 

> Fernando, I have no hard evidence but running lower
> than -p512 used to be normal for me. I swear I used to
> run -p128 and -p256 with rock solid performance.
> During the last several months, i usually run -p1024.
> I don't know what that means. Part of me wonders if
> something has changed in jackd. I guess it has
> undergone changes. Understanding these things is
> somewhat beyound me.
> A couple things that have changed for me since the
> rock solid performance days are the use of CCRMA
> rather than Gentoo 

Wow, big change! :-)

> and I changed from an nvidia to an
> ATI radeon 9500 pro display card. I've installed the
> ATI drivers and it doesn't seem to make much
> difference.

I have used radeon cards but not the latest 9500, I tend to go with
slower fan-less cards (I think 9200 is the latest I have used). 

> I suppose there could be something to the switch from
> Gentoo to CCRMA but wouldn't the issues be centric to
> the kernel and not the distribution?

They _should_ be, of course. Maybe Gentoo has some patches that I don't?
I don't think so, but it is always a possibility - I am assuming you are
using the same or similar release (2.4.26 is the current in Planet
CCRMA). It could also be the change in the video card. 

Any clues as to when do the xruns happen? Related to some kind of
activity? Or just apparently random? What sort of hardware (other than
the video card) are you running on? What soundcard?

-- Fernando