[PlanetCCRMA] Fedora 1 or 2

Mark Knecht markknecht@comcast.net
Mon Sep 27 13:17:01 2004


On Mon, 2004-09-27 at 13:00, R Parker wrote:
> --- Mark Knecht <markknecht@comcast.net> wrote:
> 
> > On Mon, 2004-09-27 at 06:46, R Parker wrote:
> > > The solutions for low latency in 2.6 are in the
> > early
> > > stages of development. I think the average 2.6
> > user on
> > > these lists is someone that's interested in
> > testing
> > > and reporting performance. The 2.4 kernel has been
> > > running stable for a pretty fair amount of time.
> > Maybe
> > > a couple years or even longer.
> > > 
> > > ron
> > 
> > Some of us are stuck. I have a new laptop with a new
> > chipset.
> 
> The first guy with the HDSP and now another new
> chipset...I'm not feeling sorry for you. Maybe a bit
> jealous. :)

<hehe!!> Jealous isn't the right place to be on this Ron. I bought the
laptop because the price/performance looked quite good. It wasn't a big
problem to go to 2.6.3 for me as I wasn't required to do audio with the
machine. I did that with Pro Tools on the same box. However, over time I
keep trying to move more of my work to Linux, and as I say I have this
gig coming up in 4 weeks so it seems like another opportunity to track
some major sessions with Ardour.

The HDSP was jsut a mistake, really. Never should have bought it.
Patrick suggested I was crazy before I did. Should have listened! Not
the first time I was stuborn. That said it works really well under
Windows so it's not a complete loss.

> 
>  I get no
> > DMA support with a kernel older than 2.6.3, and I
> > get no realtime
> > support with a kernel newer than 2.4.X.
> 
> I know nothing about DMA but was under the impression
> that 2.6.N had low latency and realtime work being
> done on it. Is the DMA needed for firewire drives or
> is it used all over the place?

This was for the on-board EIDE drives. <2.6.3 and the ATI chipset only
supported PIO. hdparm -tT returned something like 4MB/S. With DMA I now
get a respectable 25MB/S.

> 
> By realtime you mean the capability to prioritize
> tasks, right? I recall comments to the affect of
> Ingo's patches performing comparibly with true
> realtime systems.

Well, no I meant whatever the 2.6 version of the 'Capabilites' patch
ends up being. I think the 'realtime-lsm' stuff is part of that:

http://lwn.net/Articles/101723/

However (so far) it hasn't loaded for me. Granted I was also trying out
a Con Kolivas kernel at the time and certainly could have messed up the
installation somehow. I do it every day.

My main issue here is that when working in a Windows environment like
Pro Tools I'm finding that using Linux for soft synths and VSTs is one
option. However that option requires I run Wine and I will not run wine
as a root user, and without being root you end up with xruns as you
cannot get the real-time option (-R?) from jackd. As I understand it the
need for jackd -R and a kernel >2.6.3 for my hard drives to go fast has
been, so far, mutually exclusive for the mere mortal like me. However,
with Fernando's help and the bleeding edge Planet versions I might have
a fighting chance. Long term though I'm not committed to any RPM based
distro.

In the short term, like for this upcoming gig, I'd be happy to run
PlanetCCRMA if it works on this machine. 

> 
> > what's a guy to do?
> 
> I'm fresh out of chickens but some grey squirrel
> sacrifices might make strong vodo.
> 
> ron
> 

Thanks!

- Mark