[PD] latest Pd-Extended cpu usage (was: new editing features of Pd-extended 0.43, now in beta)

[Jamie Bullock]

On 28 Feb 2012, at 19:58, katja wrote:

> 
> 
> On Tue, Feb 28, 2012 at 7:12 PM, Rich E <reakinator at gmail.com> wrote:
> 
> 
> Anywho, the latest nightly build is still running at around 17% cpu for me before ever opening a patch.  It's just enough to make my fans hum. :)
> 
> I've attached a process sample from Activity Monitor, hope it helps track it down.
> 
> 
> An interesting question. On my MacBook with OSX 10.5 Pd is sometimes running as much as 27% in 'idle' state. When Pd is started, dsp if off but the adc/dac are not. Only after turning dsp on, and off again, the adc/dac are off.
> 
> As you're on OSX, you can use the magnificent performance profiler Shark.app to get a better view of CPU load of functions. Most CPU time for adc/dac is consumed by DspFuncLib, AppleHDA and mach_kernel. Apparently, the system does a lot of processing on the audio stream without us asking for it. There's denoise, equalizer and fft functions amongst others. I don't think Pd can influence these routines, except by not using the adc/dac. 
> 
> CPU load for adc/dac depends on hardware. Using an external audio interface reduces the load.
> 

Yup, I think this is related to the Portaudio driver. I reported it here:

	http://sourceforge.net/tracker/?func=detail&aid=3100679&group_id=55736&atid=478070

I don't think it's Portaudio itself that's at fault, but rather the way it interfaces with Pd.

best,

Jamie