[LAU] PHASEX-0.10.2

William Weston weston at sysex.net
Thu May 24 07:43:45 EDT 2007


On Mon, 21 May 2007, David Adler wrote:

> nice sounds - seems quite cpu-hungry, i get lots of xruns when polyphony 
> exeeds about three notes, but it might be related to my jack/priority 
> setup and not phasex.

Yes, I'll be the first to agree that there's still a lot of room for
optimization.  For reference, on my 2GHz athlon-xp box, I just
barely get full polyphony (six voices by default) out of two
simultaneous instances undersampled to 48k with jack running at 96k.  
Not great, but not bad for code that would give me a max polyphony 
of 3 (requiring 3 instances) just a few months ago.  Optimization is 
already on the roadmap, and it's the first priority after the patch 
selection system gets reworked a bit.

If you're maxing out your CPU, you'll get xruns no matter how fine 
tuned your system is, so I wouldn't blame the jack/priority setup 
just yet.  If you have a 1GHz or below processor, I would recommend 
editing src/phasex.h, changing NUM_VOICES from 6 to 3, and 
recompiling.  The configure script also supports an
'--enable-arch=' flag to get gcc to optimize for specific 
processors.

Also, you may want to use the Mono MultiKey mode whenever you can
get away with it.  This keymode uses only one voice and maps the
midi keys in play round-robin, in order of play, to the Midi Key
sourced oscillators.

BTW, could you give me some more details about your system, like cpu 
type/speed, kernel, ram, sample rate, etc.  I might be able to give 
better advice.


Cheers,
--ww



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