[PD] Pd 20% idle CPU usage on MBP

Mathieu Bouchard matju at artengine.ca
Mon Nov 8 17:30:41 CET 2010


On Mon, 8 Nov 2010, Jamie Bullock wrote:

> And I've just noticed that Pd uses the PABLIO (blocking I/O) interface 
> to Portaudio. This might be part of the problem as it certainly isn't 
> designed fo low-latency work.

But a blocking interface isn't using any extra CPU at all, so it sounds 
like the 20 % is not because PABLIO is used. However, anything blocking 
can prevent Pd from reaching the ceiling of 100 % CPU usage, because it 
spends a certain % of time waiting for more input, but the way that this 
is registered with the OS, the OS does not record this time as being used 
by Pd, and instead tries to do something else in the meanwhile, and if it 
can't, it records that time as being spent waiting for anyone to need the 
CPU ("idle").

  _______________________________________________________________________
| Mathieu Bouchard ---- tél: +1.514.383.3801 ---- Villeray, Montréal, QC


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