[PD] switch~ & cputime climbing

[Derek Holzer]

Hi Phil,

just to keep this in people's minds... I have exact same problem 
described in these emails with my Particle Chamber granular synthesis 
patch. It has 32 "switch~ed" voices. Using one instance seems to be OK, 
but two or more leads to exponentially-growing CPU usage that eventually 
makes PD unresponsive to the GUI (and eventually would probably crash PD 
if I let it go on...) I guess this could relate to the "isn't the GUI 
supposed to have lower priority than	process?" thread, since this 
particular problem makes PD a bit unusable for the kind of performances 
I want to be doing with it. The fact that PD lacks a usable 
voice-allocation method (i.e. CPU resources can be allocated and 
de-allocated to a voice, something which switch~ has a bug with, and 
which Nqpoly~ and so on does not do at all) means that I must start 
looking into SuperCollider to work with my polyphonic granular synthesis 
stuff. Sad but true...

d.

Phil Stone wrote:
> Hi,
> 
> I'm getting a slow-but-steady climbing CPU when running some synthesis 
> patches.  I (like the poster below) have sub-modules that can be 
> switch~ed on and off.  An archive search turned up the following 
> un-replied post:
>> Hi all
>>
>> Okay.  I'm stumped.
>>
>> Recently, I've noticed that my cpu meter has been steadily rising.  I  
>> think I may have found the culprit.
>>
>> A while back I thought I'd put a power switch (just a switch~ object)  
>> on my poor-man's granular delay line, as my performance patches are  
>> getting a bit bulky.
>>
>> Try this (if you have the time):
>>
>> http://www.sideshowmedia.ca/cputest.zip
>>
>> cputest.pd: (needs expr, but I think that's all)
>>
>> 1. turn on audio in pd, but leave the power (p toggle) in "lois"  
>> off.  Watch the cpu meter climb (over a period of 5 minutes or so -  
>> the toggle prints the cputime every 10 seconds).  On my computer (G4  
>> Powerbook, HCS extended 0.38.4) it starts around 5% and hits 10%  
>> after 5 minutes.
>>
>> 2. Do the same with "lois" on.  For me, cpu hovers around 13-14%.  No  
>> increase.
>>
>> 3. Repeat step 1.  After 10-15 minutes, cputime is higher than with  
>> "lois" on.  Switch "lois" on, and cpu drops.  Huh?
>>
>> I have no idea what's going on, but am I missing something  
>> important?  Thanks in advance.
>>
>> cheers
>> dafydd
>>   
> 
> Does anybody have any insight on this?  I don't remember this happening 
> until fairly recently, but don't know if it dates to when I started 
> switch~ing modules.  I'm currently running 0.39.2-extended RC1 on a 
> MacBook Pro.
> 
> 
> Phil Stone
> 
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-- 
derek holzer ::: http://www.umatic.nl ::: http://blog.myspace.com/macumbista
---Oblique Strategy # 109:
"Lost in useless territory"