Buffers and Latency in Reaper

[Studiodawg]

I really appreciate the better than average settings for buffering in Reaper. I would like to learn more about this subject. Can you please touch on what the settings 1 thru 13 for buffer settings imply and where I might be able to find more info on the science of buffering and its relationship to latency.

[Justin Frankel]

I'm not sure what you're asking here, so I'll just describe a little of how REAPER moves data around for playback. Most of this is configurable, I'm just describing the defaults.

When REAPER reads from items on disk (i.e. WAV files etc), it buffers them ahead by 600ms (i.e. it tries to keep 600ms of data ready).

If you have the "fx render-ahead" mode on, REAPER will render each track (if it is not record monitoring or dependent on a track that is) up to 200ms ahead as well. This data is stored in a track cache.

Then, when the time comes to mix a buffer (the size determined by the audio hardware), the audio thread gets to just go mix down all of the pre-rendered tracks (or if they aren't already rendered, render them).

Is this helpful? :)


-Justin

[Studiodawg]

Thanks Justin-
I checked the manual before this response, but did not see specifically what I am referring to. Reaper is installed on a laptop that I don't have with me. I think in the Reaper Preferences>Audio>Playback there may be a setting that ranges from 1 (very relaxed) to 13 (very aggressive) and I think it has something to do with buffering. It may, in fact be the buffer number. Anyway, I'll check this and try to precisely state what I am looking at and curious about. Thanks for your time.
Sam

[Justin Frankel]

Originally Posted by Studiodawg

Thanks Justin-
I checked the manual before this response, but did not see specifically what I am referring to. Reaper is installed on a laptop that I don't have with me. I think in the Reaper Preferences>Audio>Playback there may be a setting that ranges from 1 (very relaxed) to 13 (very aggressive) and I think it has something to do with buffering. It may, in fact be the buffer number. Anyway, I'll check this and try to precisely state what I am looking at and curious about. Thanks for your time.
Sam

Ah yes.. this setting controls the way the threads that do some of this other work (reading from disk and rendering FX) behave.. higher numbers make them try more often to fill these buffers up.. Increasing this value means that those threads will have slightly more overhead, but may perform better at really low latencies (i.e. < 64 samples).

[Studiodawg]

Thanks Justin...I have a licensed copy. "See" you in the Reaper Forums.