[soegaard]

The `portaudio` is a few years old, so I have a hunch that the comment refers to the old backend "Racket BC". The new backend "Racket CS" has a new garbage collection mode "incremental", which I understand is better for this usage scenario. I don't have any numbers though.

[soegaard]

I got some more information from Flatt.

The new incremental mode means the 16ms deadline is within reach. In fact if the screen is not involved, then 1-2ms is reachable.

On macOS a screen-refresh can cause a 16ms pause.

[xfer]

Didn't incremental GC exist before CS work even began? I certainly remember seeing it although it was not default. Or is this a different implementation?

[samth]

Yes, incremental GC exists in both the CS and BC variants. It works quite differently in each one, though, because the general GC architecture in each is different.