linuxaudio.org

On Wed, 2010-07-14 at 22:16 +0200, Ralf Mardorf wrote:

quoted text
> On Wed, 2010-07-14 at 21:45 +0200, Robin Gareus wrote:

> > On 07/14/2010 03:23 PM, Ralf Mardorf wrote:

> >

> > [..]

> > > $ su -c "chgrp audio /dev/hpet"

> > Its also writable for the group, right?

> >

> > > $ su -c "sysctl -w dev.hpet.max-user-freq=64"

> >

> > Documentation on this value is hard to come by, but I think it's unit is

> > Hz. So you'll want

>

> Yep :). I've got no idea what would be better a high or a low value, but

> at least 64 when using HR timer was better than using the regular timer.

> Unfortunately not many apps are able to run, when HR timer is used.

> Usage of HR timer can freeze the system, e.g. Rosegarden does this on my

> machine. I also need to start 'qtractor filename'. If I first start

> Qtractor and than try to load a session, here are issues because HR

> timer already is captured.

>

> I guess one would be more flexible, if not using HR timer. I didn't

> tested if there will be a difference when using the PCI MIDI. I'll do

> this also ASAP. As I mentioned before, for USB MIDI there is a big

> difference.

>

> No thunder, no storm anymore, but there was a rainbow some minutes

> ago :)

>

> - Ralf

>

> >   su -c "sysctl -w dev.hpet.max-user-freq=1024"

> > or even more :)

> >

> > try:

> > echo 2048 | sudo tee /sys/class/rtc/rtc0/max_user_freq

> > echo 2048 | sudo tee /proc/sys/dev/hpet/max-user-freq

> >

> > [..]

> > ciao,

> > robin

> >

> >

> 

Could it be that a low value is better because it's some kind of 'be

ready for an IRQ every 64 times (of what unit ever)'?
IIRC a long time ago I tested 64 and 1024 and couldn't hear or see (for

the waveforms) a difference.
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