Given that real time inputs(low latency, say 96000khz SR and 128 "byte"(generally are these actually bytes or frames?) is about 1ms to process the input) must be processed quickly, I can't see how multiple threads can be used.
An audio engine only has one callback from the hardware to fill the output buffer!? The callback surely doesn't spawn another thread because this could take quite a bit of time. Even if it does, it can't guarantee the thread will be finished processing in time.
The best I can tell is that the way audio is done requires the use of a single thread for all audio processing except that which can be pre-computed.
Are multiple threads in DAWS actually be used for doing simultaneous processing of the callback buffer? If so, how is this achieved without wasting a ton of cycles just on the threading management part of the code?
Are "multi-threaded" DAWS actually using multiple threads for audio processing of real time inputs or are they using one thread and the others for doing various other things(graphics, UI, etc...)?
By multi-threading I mean running them on different cores of course.