[PD] new raspberries
Claude Heiland-Allen
claude at mathr.co.uk
Fri Feb 6 22:50:02 CET 2015
I've not got any version of the rpi, but maybe it's scaling down the
clock frequency of unused cores, which then takes some time to spin up
to full speed when a task is moved by the kernel?
I also had issues on amd64 desktop and core2duo laptop with pd -rt not
being taken into account by the kernel ondemand cpu speed governor, or
some other issue perhaps, whereby the cpu speed would stay at ~800MHz
even though it really needed to be higher to reduce xruns etc.. pd -nrt
would scale up the cpu speed correctly.
On my quad-core amd64 desktop I run this before realtime work (or nrt
benchmarking) to set all cores to maximum speed (with the 'performance'
governor):
for c in 0 1 2 3 ; do sudo cpufreq-set -c $c -g performance ; done
Then when I want to reduce fan noise / heat etc and I'm not doing much
intensive, I reset to the default 'ondemand' governor:
for c in 0 1 2 3 ; do sudo cpufreq-set -c $c -g ondemand ; done
Might also be worth looking into setting scheduler cpu core affinity for
pd, jackd, pd-gui, ... but I don't know how to do that.
Claude
On 06/02/15 21:38, katja wrote:
> Aplay can play a .wav file without trouble, so it is not a general
> problem with the audio hardware or drivers on Pi 2b.
>
> I installed command htop to see CPU load per core. It's interesting,
> the load switches from one core to another, and sometimes they all
> seem to be almost idle even with a heavy Pd patch running.
--
http://mathr.co.uk
More information about the Pd-list
mailing list