[PD] How to reduce CPU use on unused subpatches-abstracts?

[Roman Haefeli]

On Wed, 2013-08-07 at 08:40 +0200, IOhannes m zmölnig wrote:
> On 08/07/13 03:15, Miller Puckette wrote:
> > Hmmm...  I was umnder the impression that, except for the overhead of block~
> > and switch~ objects, there would be no difference in DSP execution time
> > between a patch having lots of subpatches and one with the same amount of
> > computation all thrown in one window.  I haven't made any measurements but
> > theoreticall at least there shouldn't be any difference.
> 
> i once did make measurements, and they showed that your assumption is
> correct.
> 
> or at least, it showed that it *was* correct at that time. this was on a
> P2-400MHz in 1998 or so, where a 16 channel spatialization patch would
> eat about 95% of the CPU - regardless of whether you used a single huge
> patch or organized the code into subpatches/abstractions.
> 
> eventually i went for using abstractions, and let the PC run at 95% for
> the 2 weeks show.

I once made some informal tests to measure the overhead of [switch~]. It
turned out it is quite big and if you're running hundreds or thousands
instances of [switch~] you probably gain nothing by turning DSP off in
subpatches. I don't know what the sweet spot is it seems using [switch~]
is only worth for subpatches with a minimum amount of (DSP) complexity.

Roman