cpu frequency scaling

Gerhard Lang lang.gerhard at gmail.com
Thu Nov 12 01:34:30 GMT 2009

Setting this theme into a focus of interest was intended. I'm pleased
for publishing something useful :-)
Working with wine/wineasio/vsti, synthesizers, heavy load effects, multi
track ardour etc. we were lost without getting cpufrequency  in real
time to highest values.
I prefered userspace numeric entries, but think setting to "performance"
will do too. I always forget this after booting into -rt kernel,
starting audio work  and then I'm remembered by lots of xruns or jackd
I'm still testing the manipulation of 'ondemand' by lowering
up_threshold per editing rc.local.
It seems to work fine.
On my notebook (intel dualcore) I had to modify:
'(sleep 2 && echo 50 >
/sys/devices/system/cpu/cpuX/cpufreq/ondemand/up_threshold) &'
as recommended in the archwiki link.
set X to 0,1,2,... for each cpu core a new line if they are not linked
as in my old amd system.
Hope developers read this, modify defaults, edit howtos ... if I just
were younger and had more time...
I'm afraid many new ubuntustudio testers who got their hardware running
after learning how to set access rights and priorities resignate because
of poor performance which could be optimized by a little tuning like this.

Q schrieb:
> Thank you for posting this question and the background to it.
> Ever since I installed 9.10, I've been unable to run certain Ardour 
> sessions (the biggest ones), with it constantly getting kicked off JACK 
> no matter what settings I used. I actually resorted to compiling a newer 
> version of Ardour, the first time I've ever done such a thing!
> I installed a freq scaling control app (I didn't even need to tinker 
> with it) and with scaling turned off everything works the way it should, 
> quick and simple.
> Thanks again!
> Q
> Gerhard Lang wrote:
>> I always run into jackd low latency issues when I forget to set  cpu
>> frequency scaling panel-applets to highest options. Is there a way to
>> set this by default on start up without recompiling the rt-kernel?

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