[PD] Pd 20% idle CPU usage on MBP

[Jamie Bullock]

On 10 Nov 2010, at 04:39, chris clepper wrote:

> Is this using the built-in speakers or the headphone jack?  Plug in an optical cable and see if the CPU doesn't drop a lot.  Or try a USB or Firewire interface.  
> 

OK, just tried my Edirol FA-66 firewire interface. CPU does indeed drop to 12%.

Still that's a ridiculous overhead for simply talking to the audio hardware.


> By default CoreAudio does a lot of processing on audio when using the built-in outputs.  It used to mainly be limiting to keep the shitty speakers from blowing, but it has expanded over time.  There is obviously a way to tell CoreAudio to cut that out, but how that is done via PortAudio is a question for the PA developers. 
> 
> The ml_set_interrupts_enabled is the blocking.
> 

Does that mean that Mathieu was wrong earlier about the PABLIO interface not causing any significant overhead?

Jamie

> On Tue, Nov 9, 2010 at 10:48 AM, Jamie Bullock <jamie at postlude.co.uk> wrote:
> 
> 
> 
> pd doing 'nothing':
> 
>        10.6%   10.6%   mach_kernel     ml_set_interrupts_enabled
>        9.4%    9.4%    DspFuncLib      iZRedist::DSP::Denoise::processWithLookahead(int, float* const*, int)
>        6.7%    6.7%    DspFuncLib      iZRedist::DSP::FftImpl::FftComplex_InPlace(iZRedist::DSP::Cmplx*) const
>        6.3%    6.3%    DspFuncLib      DspFuncHelper::process_IIR_xmm_LR(float*, float*, float*, float*, unsigned int)
>        3.8%    3.8%    DspFuncLib      iZRedist::Util::Log(float)
>        2.8%    2.8%    AppleHDA        NativeInt32ToFloat32_X86
>        2.5%    2.5%    DspFuncLib      iZRedist::DSP::FftImpl::FftReal(float const*, iZRedist::DSP::Cmplx*) const
>        2.3%    2.3%    DspFuncLib      DspFuncDRC::_dynamicRangeControl(float*, float*, unsigned long, unsigned long)
>        2.0%    2.0%    mach_kernel     lo_mach_scall
>