[PD-dev] [ pure-data-Bugs-3100679 ] 20% CPU with Portaudio on OS X

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Bugs item #3100679, was opened at 2010-11-01 11:35
Message generated for change (Tracker Item Submitted) made by postlude
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Category: puredata
Group: None
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Jamie Bullock (postlude)
Assigned to: Nobody/Anonymous (nobody)
Summary: 20% CPU with Portaudio on OS X

Initial Comment:
Analysis with Shark profiling software shows there is a lot of activity in the underlying audio drivers when using the Portaudio driver with Pd on OS X. Comparison with AudioMulch, which also uses Portaudio suggests that is only in part a Portaudio problem. AudioMulch idles at ~10% on my machine. I suspect that the problem with Pd+portaudio may be due to a small buffer size used by Pd. I thought Pd's 'Delay' setting in audio preferences was supposed to handle this, but changing delay to 500ms, has no effect on CPU use, so maybe the problem is elsewhere.

IMO, this problem is a bit embarrassing for Pd. Pd either needs to made to work efficiently with Portaudio, or direct CoreAudio support should be considered.

Note: this isn't a duplicate of bug 3100671, which only concerns idle CPU

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You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=478070&aid=3100679&group_id=55736