Hey Folks, Hoping for some help or insight on the following issue:
In Logic Pro, when you start playback, or move the playhead to a new location during playback, the performance meter shows an initial spike in CPU usage across some or all available threads, which then settles down to a lower level that remains sane and stable for the duration of playback.
It’s most obvious in a session with a couple dozen or more tracks, especially with plugins instantiated on most of them.
Now, when I put an instance of my plugin on, say, 10-15 of these tracks, these spikes become quite large — often pinned to the top of the meter on several threads — and will often coincide with logic failing to proceed with playback in any meaningful way, instead simply looping its start attempt over and over again, with little to no audio output. Sometimes it will ‘catch’ and playback will continue, CPU goes to a normal level, etc. Other times it just stays stuck in that failed-start loop.
You can see an example of both versions of this in a short screen capture I took. First the ‘spike then calm’, and then I move the playhead and you can watch it dance over the same initial section repeatedly until I cut off the recording.
So there’s 2 Questions Here: Can anyone point me to what Logic is doing there at play-start that’s different than during steady playback, which causes that spike-then-calm behavior? And has anyone run into this issue specifically with a plugin and found a fix?
Initially I chalked this up to high CPU use, but no other DAW has issues running multiple instances of the thing, and while optimization improvements have mitigated the issue to some degree in Logic regardless, I have been unable to figure is what is different about the START of playback there which could cause this to happen.
Any ideas? Guidance? Obvious solutions I’ve overlooked?