Hey I finally ran into a patch that was worse with more threads. The issue I think was having a bunch of VCV Host-FX active.
8 threads was full of digital crackle & increasing buffer size was of limited help.
It occurs to me that VST plugins run in their own thread, & when Rack is using all available threads, plugins get juggled by the scheduler, with more software threads than physical CPU cores.
Does this sound right?
That sounds right. I think maybe the Clap plugins don’t have this issue, as I think they can share a thread pool with the host?
This is a very well known issue - that plugins making their own threads can fight with the host. I used to deal with this kind of thing an awful lot when I worked for one of those DAW companies.
So, yes, I agree that your thinking here is probably correct.
Does VCV as a VST make its own threads?
I think you can tell rack to not run the plugin on a separate thread.
Another problem that there’s probably no solution beyond “Don’t do it“: some VST plugins can use 10 percent or more of the GPU bandwidth. Rack and windows seem to use 25% of the GPU, so open too many plugin windows and the user interface gets really slow.
The don’t do it solution is to limit the # of plugin windows open.