alistair macdonald

I'm finding it hard to understand Advanced Scheduler Settings in practice (and actually my theory isn’t much better). I use a patch (on my 2017 Macbook Pro, 2.9GHz, 16GB) which comprises an ever evolving array of vst plugins, granular patches, 20 looping buffers, soundfile players, harmonisers, multiple audio inputs and outputs and more. I control this wirelessly using the Lemur app. Audio status reports 25-30% cpu usage. 

The documentation says “If you are primarily going to be using Max for MIDI or audio processing, Overdrive should be enabled” however, with Overdrive on, the response to Lemur is very jerky: e.g. a volume fader moving slowly up on the iPad will jump erratically up on the Mac arriving late at its destination, and the sound jumps with it (gaps & jumps of up to a second). Switching Overdrive off seems to resolve this problem, but since the patch is all about audio processing I’m confused.

The only Scheduler setting that makes a difference to this is Poll Throttle. With Overdrive on, if I change the Poll Throttle setting from (default) 20 to 30, the response to Lemur starts to be smoother; if I change to 50 it’s much better. 

Poll Throttle sets the number of high-priority events processed per by the scheduler at one time. High priority events include MIDI as well as events generated by metro and other timing objects. A lower setting (e.g., 1) means less event clumping, while a higher value (e.g., 100) will result in less of an event backlog. The default value is 20 events

.” I don’t know what this means in relation to my patch, so I have no idea if I’m better off with Overdrive ON with Poll Throttle set to 50 (or more?), or with Overdrive OFF.

I'm finding it hard to understand Advanced Scheduler Settings in practice (and actually my theory isn’t much better). I use a patch (on my 2017 Macbook Pro, 2.9GHz, 16GB) which comprises an ever evolving array of vst plugins, granular patches, 20 looping buffers, soundfile players, harmonisers, multiple audio inputs and outputs and more. I control this wirelessly using the Lemur app. Audio status reports 25-30% cpu usage. 

The documentation says “If you are primarily going to be using Max for MIDI or audio processing, Overdrive should be enabled” however, with Overdrive on, the response to Lemur is very jerky: e.g. a volume fader moving slowly up on the iPad will jump erratically up on the Mac arriving late at its destination, and the sound jumps with it (gaps & jumps of up to a second). Switching Overdrive off seems to resolve this problem, but since the patch is all about audio processing I’m confused.

The only Scheduler setting that makes a difference to this is Poll Throttle. With Overdrive on, if I change the Poll Throttle setting from (default) 20 to 30, the response to Lemur starts to be smoother; if I change to 50 it’s much better. 

“Poll Throttle sets the number of high-priority events processed per by the scheduler at one time. High priority events include MIDI as well as events generated by metro and other timing objects. A lower setting (e.g., 1) means less event clumping, while a higher value (e.g., 100) will result in less of an event backlog. The default value is 20 events.” I don’t know what this means in relation to my patch, so I have no idea if I’m better off with Overdrive ON with Poll Throttle set to 50 (or more?), or with Overdrive OFF.
Any ideas?

I'm finding it hard to understand Advanced Scheduler Settings in practice (and actually my theory isn’t much better). I use a patch (on my 2

scheduler-settings

On a Retina Macbook, if you have a patch that is performing a lot of user interface drawing, such as rapid updates to JSUI, you are possibly backlogging the queue, which can have an effect on scheduler performance. On these machines, GUI rendering costs are roughly 4x expensive, unless you disable high resolution support (patchers will look worse). To turn off high resolution support for Max, go to the Finder, and Get-Info (cmd+i) on the Max application icon and check the "Open in Low Resolution" box." 

I tried this too but it didn't make any difference...

PS "On a Retina Macbook, if you have a patch that is performing a lot of user interface drawing, such as rapid updates to JSUI, you are possibly backlogging the queue, which can have an effect on scheduler performance. On these machines, GUI rendering costs are roughly 4x expensive, unless you disable high resolution support (patchers will look worse). To turn off high resolution support for Max, go to the Finder, and Get-Info (cmd+i) on the Max application icon and check the "Open in Low Resolution" box."  I tried this too but it didn't make any difference...