[PD] Variable CPU?

[Martin Schied]

Thibault Walter wrote:
> Hello
>
> I made a little discovery.
>
> It works with pd-extended and with pd-vanilla+GEM. Il have a MacBook Pro
> 2.66 GHz Intel Core 2 duo, with Mac-OS X 10.5.8.
>
> When I open one of my video-patch (it works with any one of my video or
> sound patchs), if I look at the CPU utilisation, I get something like 7 ou
> 8. Nothing is running, the GEM window is not even created.
>
> If I wait something like 1 or 2 hours without using pd ; or, if I pause my
> computer (I close it), wait 30 seconds, and open it, I get something like 0
> or 1 as my CPU.
>   
This might be a cpu frequency scaling issue. I had similar "phenomena" 
on Ubuntu once, where the CPU didn't go into its lowest frequency 
setting anymore after waking up from suspend mode.

So for example on a fresh reboot your cpu would be able to switch 
between 800MHz, 1300MHz and 2.6GHz or so, most of the time it's on the 
lowest setting and therefore your CPU is quite busy (still on 800MHz). 
Then after the suspend (closing it) it never uses the 800MHz setting but 
only the highest - and so the cpu cycles percentage where the cpu is 
used is far less. If you don't want to do the "suspend trick" every time 
there might be a "performance" setting or so which does the same thing. 
On ubuntu you can do this using 'cpufreq-set -g performance' on the 
command line, not sure what to do on OS X.

 - just a guess, might be totally wrong too. -

cheers
Martin

> Then, if I use my patch, when I get normally CPU = 70, and with this method
> I get CPU = 20. And of course, the performances are absolutely not the same.
>
> In fact, without this method, my MacBook Pro is not very much more powerful
> than my old 1.33GHz PowerPC G4.
>
>
> It works with audio-patchs too.
>
> There is an other method : if I turn dsp on, and then off, I get the same
> result. This method can't work with audio-patchs, because when I turn on dsp
> I always get high CPU. So I have to turn dsp on before pausing and turning
> on my computer. (I don't know if I'm clear...)
>
>
> Weeell, I realized that it works with my PPC too, but the differences are
> not so important.
>
> Has someone any explanation?
>
> excuse me for my english
>
> T
>
>
>
>
> _______________________________________________
> Pd-list at iem.at mailing list
> UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
>
>