8 Apr
2007
8 Apr
'07
8:35 p.m.
On Sun, 2007-04-08 at 23:39 +0200, Karl Hammar wrote:
James Stone <jamesmstone(a)gmail.com>om>:
no, this is not really accurate.
the PCI latency timer determines how long a device may own the PCI bus
for, it has nothing to do with audio latency. therefore, if your system
allowed the video interface to hog the PCI bus for a relatively long
time, but limited the audio interface to only short periods of bus
ownership, then audio performance will suffer.
the script i posted first resets *all* devices to an acceptable
middle-of-the-road timer setting, then specifically allows the audio
interfaces to own the bus for even longer.
On Sun, Apr 08, 2007 at 01:38:34PM +0200, Karl
Hammar wrote:
> Andrew Burgess <aab(a)cichlid.com>om>:
> > Paul Davis wrote:
> > >> What could cause clicks without xruns? I'm baffled.
> > >PCI bus hogging, for one thing. consider running a script like this
> ...
> > setpci -s $p latency_timer=ff
...
I am slightly confused. Is it necessary to
increase the latency
timer for a pci sound card? This seems slightly
counter-intuitive. Wouldn't this reduce the performance of the
sound system through that card?
Performance and latency is different things. In audio we accept all
latencies below 30ms (I think), less than that does not gain anything.
But we can gain bandwith by using longer bursts, thus a higher latency
(within bounds) gives us greater performance.