[linux-audio-dev] Re: [announce] [patch] Voluntary Kernel Preemption Patch

[Thomas Charbonnel]

Florian Schmidt wrote :
> Hi,
> 
> interesting that you mention the Xserver. I use a dual graphics card setup atm [Nvidia GF3 TI and some matrox pci card]. The nvidia card seems to work flawlessly even with HW accelleration [i use nvidias evil binary only drivers]. The matrox card OTH disturbs the soundcard severely. Whenever i have activity on my second monitor i get sound artefacts in jack's output [no cracklling, it's rather as if the volume is set to 0 for short moments and then back to normal]. There's a certain chance that this artefact produces an xrun. I suppose it's because the card is on the pci bus.
> 
> I figured it's maybe an irq issue problem, but whatever slot i put the gfx card in - it made no difference [btw: how do i find out which resources this card uses? it is not shown by /proc/interrupts]. I also tried putting the soundcard in many different slots to maybe get it on higher prio irq, but it always gets irq 5 [according to /proc/interrupts]..
> 
> Should i try a different 2nd gfx card? Should i avoid pci gfx cards at all costs? Will i just have to live w/o second monitor?  How do i find out which hw resources X is really using?
> 
> Florian Schmidt

You could try to adjust the pci latency timer value of your graphic card
and sound card, see this link for a paper on the subject by Daniel
Robbins :
http://www-106.ibm.com/developerworks/library/l-hw2.html

Thomas