[PD] how to optimize system for pd performance?

[Miller Puckette]

Wow, this clears up an old mystery for me - thanks for starting this
thread!

Another way to grab CPU power is to run "pd -nosleep" which causes it to
spin instead of sleeping when it goes idle.  On my system at least, I
see the CPU immediately go to full speed.  (But only do this on a system
with more than one CPU.  And I'm not sure how this will play with jack -
I'm using Alsa directly.)

cheers
Miller


On Sun, Dec 07, 2008 at 05:17:38PM +0100, Roman Haefeli wrote:
> you might have guessed it, but for the sake of correctness:
> 
> this is:
> - linux / ubuntu hardy
> - intel core 2 duo (800 -> 2401 MHz)
> - pd vanilla 0.42 test5
> 
> 
> On Sun, 2008-12-07 at 16:58 +0100, Roman Haefeli wrote:
> > hi all
> > 
> > i encountered, that 'ondemand' cpu scaling doesn't work correctly when
> > running pd with realtime priority. even if pd is using 80% or more
> > resources (of one core), the cpu frequency is not raised and staying at
> > 800MHz. i can force it to go up by running an instance of 'burnMMX' (or
> > something else, that burns as many cycles as possible). when running pd
> > with '-nrt', automatic scaling works fine. also, as a workaround, i can
> > set the scaling_governor to 'userspace' and then set the cpu frequency
> > manually. 
> > 
> > could it be, that when pd is running in realtime mode, its priority is
> > higher then the one of the process, that controls the cpu frequency, so
> > that cpu time is assigned rather to pd and only at times, when pd is not
> > using it, the governor can adjust the frequency (which would be the
> > loweset, since pd is not using much cpu at that time)?
> > 
> > i wonder, what other people do in a performative situation? do you
> > simply turn automatic scaling off and set frequency to the highest
> > value? or is it only me having this issue?
> > 
> > 
> > while we are at priorities:
> > i figured out, that all four combinatios are possible:
> > pd -rt, jackd -R
> > pd -nrt, jackd -R
> > pd -rt, jackd
> > pd -nrt, jackd
> > 
> > i guess, that the first one should be used for best performance, right?
> > but how to set priorities between jackd and pd? can this be fine-tuned
> > at all (i know you can fine-tune jackd) ? if so, which should have
> > higher priority? 
> > 
> > roman
> > 
> > 
> > 
> > 
> > 		
> > ___________________________________________________________ 
> > Telefonate ohne weitere Kosten vom PC zum PC: http://messenger.yahoo.de
> > 
> > 
> > _______________________________________________
> > Pd-list at iem.at mailing list
> > UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
> 
> 
> 	
> 		
> ___________________________________________________________ 
> Der fr?he Vogel f?ngt den Wurm. Hier gelangen Sie zum neuen Yahoo! Mail: http://mail.yahoo.de
> 
> 

> _______________________________________________
> Pd-list at iem.at mailing list
> UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list