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Correspondence with Nick Copeland

64 bytes removed, 10:25, 1 February 2011
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<span style="color:blue">Hi Murray Saul, <br /><br />The cause of the processes getting terminated is probably Jack complaining about CPU utilisation. Some of these synths ran to 10% CPU per voice, that is on my Xeon 2.2GHz machine. When Jack cannot keep up due to process load then it terminates processes. Somewhere in the 0.50 stream I finally got around to filter optimisation and the results were what I was after, the CPU utilisation per voice comes down to below 2% on the same CPU: it has been tested with a 32 voice Prophet-5 running as a Unison synth, 64 oscillator all running together slightly detuned, it took 65% CPU to do it admittedly. <br /><br />Bristol does not raise any limit on what you do. You can run 7 different bristol emulators over Jack (use the -audiodev option to separate them) or if you use the -engine feature then you can run 7 emulators on the same bristol engine. The difference is a bit like having lots of synths or having one multitimbral synth with 32 voices. Bristol supports both methods of use, the default is multiple synths rather than a multitimbral synth. <br /><br />Now how far that will get you depends a little on what you want to do. If you want 7 synths running at the same time then typically each synth engine will get 32 voices, depending on your Jack version then all of the synths may have to run on a single core so if you stay within a limit of, say, 48 voices total it will work. Check out JackDMP/Jack2, whatever it is called these days for distributed processing where you can get multiples of the 48 voices as Jack will use multiple CPU cores. <br /><br />I am pretty certain you will get better results if you go for 0.60.5, the most recent release. I would be interested in seeing an example shell script for how you start all of these, it would show which method you are using and I could also give some feedback on other options you could use.  <br /><br />Kind regards, nick. "we have to make sure the old choice [Windows] doesn't disappear”.Jim Wong, president of IT products, Acer </span>
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