[PD] CPU saving strategies

Mathieu Bouchard matju at artengine.ca
Fri Aug 6 19:12:38 CEST 2010

On Tue, 3 Aug 2010, Malte Steiner wrote:

> A modern system should be able to handle multimedia like video and 3D 
> plus GUI without interrupts in the audio stream.

That may be 1, 2 or 3 separate problems (it depends on how you try to 
solve it).

The main thread currently runs everything except Tk, which means that any 
visuals running in the main thread (GF,GEM,PDP) running at 30 fps can 
cause up to 33.3333 ms of latency when CPU usage < 100%. Generally, 
producing N fps can introduce up to 1000/N ms of latency.

Splitting signals vs the rest, can cause problems with anything that uses 
more than just signals to do its audio. It's a non-solution : it 
introduces so many new problems at once. You have to do an audio vs video 
split, ideally (because it's a split according to variation of needs of 
latency). And in such a case, part of the message-system has to run in 
lockstep with the signal-system, while another part of the message-system 
has to run in lockstep with the video output.

> The separation from Backend and GUI Frontend in PD is leaving a bit to 
> desire and my question if its possible to solve this, in maybe 10 years 
> or so?

I haven't met anyone willing to address that problem, ever.

(Note that the video and 3D subsystems are not usually considered to be 
part of the frontend)

> Or will the new thread object help?

which one ?

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| Mathieu Bouchard, Montréal, Québec. téléphone: +1.514.383.3801

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