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. <br><br>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. <br>
<br>The ml_set_interrupts_enabled is the blocking.<br><br><div class="gmail_quote">On Tue, Nov 9, 2010 at 10:48 AM, Jamie Bullock <span dir="ltr"><<a href="mailto:jamie@postlude.co.uk">jamie@postlude.co.uk</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div class="im"><br>
<br>
<br>
</div>pd doing 'nothing':<br>
<br>
10.6% 10.6% mach_kernel ml_set_interrupts_enabled<br>
9.4% 9.4% DspFuncLib iZRedist::DSP::Denoise::processWithLookahead(int, float* const*, int)<br>
6.7% 6.7% DspFuncLib iZRedist::DSP::FftImpl::FftComplex_InPlace(iZRedist::DSP::Cmplx*) const<br>
6.3% 6.3% DspFuncLib DspFuncHelper::process_IIR_xmm_LR(float*, float*, float*, float*, unsigned int)<br>
3.8% 3.8% DspFuncLib iZRedist::Util::Log(float)<br>
2.8% 2.8% AppleHDA NativeInt32ToFloat32_X86<br>
2.5% 2.5% DspFuncLib iZRedist::DSP::FftImpl::FftReal(float const*, iZRedist::DSP::Cmplx*) const<br>
2.3% 2.3% DspFuncLib DspFuncDRC::_dynamicRangeControl(float*, float*, unsigned long, unsigned long)<br>
2.0% 2.0% mach_kernel lo_mach_scall<br>
<br></blockquote></div>