[ardour-users] Latency: AGP vs PCI video card and XFS journalling vs not

[Jan Depner]

Oops.  I'm sorry I didn't notice that you're using SCSI - your SCSI
controller wouldn't happen to be an Adaptec would it?  If so you need to
look at this - http://www.staudio.de/kb/english/conflicts/index.html  
The ST Audio stuff uses the same chipset as your Delta 66 but even if it
didn't, given the information on this page, it would probably still be a
problem.  Please note that almost all Adaptec controllers use the same
driver software and that Adaptec doesn't usually change their strategy
when designing a new board so 2940, 29160, et al probably do the same
things.

Jan


On Mon, 2004-02-23 at 12:24, delire wrote:
> i would certainly be disappointed that my PCI graphics card would hit
> the bus so hard that such great headroom was practically
> worthless!
> 
> i don't know how XFS compares to EXT3, but i doubt the PCI graphics card is
> such a guzzler as to eat your clock cycles like this. 
> 
> i'd try out EXT3 before opening your wallet for a 3D card.
> 
> (jeeziz dual SCSI!)
> 
> delire
> 
> 
> On Sun, Feb 22, 2004 at 03:51:26PM -0500, lee at fallingforward.net wrote:
> > Your system has far better hardware than mine and I can get JACK down to
> > about 11ms latency with no dropouts. It seems our differences are that I
> > have an AGP video card and ext3 filesystem. I would highly recommend an
> > AGP video card, I got a Radeon 9000 new for US $80.
> > 
> > -lee
> > 
> > On Sun, 22 Feb 2004, Eric wrote:
> > 
> > > I have built a box that I thought would be able to support some very
> > > low-latency recording in the eventual hope of software monitoring with
> > > some effects in the loop (is anyone able to do this?).  It's a dual
> > > athlon 2400 w/ 1GB of DDR266, dual 10K SCSI drives, and my M-Audio
> > > Delta66.  I'm using the Debian unstable packages (jack 0.94 and ardour
> > > beta9+3) with a 2.6.3 kernel and have played around w/ all the
> > > standard latency issues (no extra stuff running, swapped PCI cards
> > > around for interrupts, etc.).  However, I'm not able to go lower than
> > > the default jack 3 periods of 1024 (with rt enabled, obviously) when
> > > working on my typical projects of 8-12 48KHz mono tracks, even without
> > > any effects in the loop.  It is dissapointing to have to go back to
> > > hardware monitoring w/ no effects...I have two questions:
> > >
> > > 1.  Could it be my old Voodoo3 PCI video card is hogging the bus?
> > > Rendering the mixer window definitely has an effect on my audio...if I
> > > drag it around or minimize/maximize it I can actually slow down the
> > > audio playback (which was surprising to me) or cause xruns and
> > > timeouts.  I've taken to just minimizing everything while I'm
> > > recording.  I didn't care about my graphics card, but now I'm
> > > considering an AGP one (nVidia GeoForceFX 5600 or ATI Radeon 9700)
> > > just to try and improve this...
> > >
> > > 2.  Could it be my XFS filesystems?  If I have 8 or so tracks on one
> > > drive, it can't even handle playback w/o giving disk errors.  I've
> > > tweaked all the XFS options, and currently have a large (64MB) log for
> > > each filesystem that resides on the opposite disk.  Would turning the
> > > log size up or down help?  Is there a way to just turn off journalling
> > > in XFS, or would ext2 be better?  I did notice that exporting to my
> > > default param (i.e. small log) ext3 root partition seems to be faster
> > > than to my XFS.
> > >
> > > --
> > > http://ir.iit.edu/~ej
> > > _______________________________________________
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> > > ardour-users at lists.ardour.org
> > > http://lists.ardour.org/listinfo.cgi/ardour-users-ardour.org
> > >
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