Re: [fluid-dev] Very high CPU usage and dropouts on Mac version

[Pedro Lopez-Cabanillas]

On Thursday 26 May 2011, Ed Costello wrote:
> Hi list,
> 
> I am using the Mac version of qsynth and I am getting very high CPU usage
> when I send midi data to the synth, 50-60 % and even as high as 90%, this is
> causing very bad audio dropouts, I thought at first it had something to do
> with the soundfont I was using but I tried the same setup on Ubuntu and
> everything played fine, the CPU was around 12% most of the time. I tested
> this with Logic sending Midi to the latest qsynth built from fink on the Mac
> and on Ubuntu the qtractor and qsynth from the natty repo. I also tested
> using just the command line version of fluidsynth 1.1.3 on the Mac and I got
> the same CPU problems.
> Thanks
> Ed
> 

Intel or PPC?

There is also a qsynth mac universal binary package at sourceforge, can you 
please try it as well?
http://sourceforge.net/projects/qsynth/files/qsynth%20%28stable%29/0.3.6/qsynth-0.3.6-univ.dmg/download

My Mac Mini (intel core2duo) and the usual configuration consumes around 15% 
CPU (between 10% and 20%) as reported by the activity monitor.

In order to reduce the CPU usage, you may want to set a bigger buffer size (-z, 
--audio-bufsize=[size]) and/or number of periods (-c, 
--audio-bufcount=[count]). The default values (64x16) are good for low latency, 
but you may save some CPU cycles using greater values. The reverb and chorus 
effects are also very CPU hungry. Please, can you provide details about your 
fluidsynth settings and system?

Regards,
Pedro