[LAU] Installing realtime kernel - getting it to work.

Lee Revell rlrevell at joe-job.com
Tue Apr 3 21:15:58 EDT 2007


On 4/3/07, Brad Fuller <brad at sonaural.com> wrote:
> Geoff Beasley wrote:
> > On Wednesday 04 April 2007 09:52:16 Brad Fuller wrote:
> >
> >
> >> Right, these are all set except for: hpet (my cpu is too old), but I'll
> >> set it anyway and "Tickless System." Is this what you are referring to
> >> when you speak of "tickless timers"?
> >>
> >
> > yup. it'll help.   what are the exact symptoms ? you should be having no
> > problem at all...
> >
> my only problems now are outside of jack, - i think jack works ok. Using
> the xine engine in amarok produces lots of clicks. Moving to the Helix
> engine works much better.
> Audacity, w/o jack, clicks too with any typing, net, window movement...
> the usual.
>

Did you make sure that the soundcard IRQ is higher prio than all other
IRQs and that Audacity has realtime mode enabled (actually I have no
idea whether it has such a thing but it should)

> I'm also concerned with the playback rate. Some apps playback too slow
> (amarok and snd, neither with jack) while audacity plays back at the
> right sample rate (with or w/o jack).

Probably your hardware only supports 48Khz but these apps use a hw
device which disables software resampling.  Audacity would work as it
uses OSS compatibility layer which resamples in kernel space.

Lee



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