reduction of buffer size = better performance in playback!?

Cubase
#1

hi folks,
first of all, i want to say thanks. i’ve been having performance problems. but i’m getting close to happy. and no doubt, with the help of this forum. running: macbook pro (2010), osx 10.6.8, cubase 6, steinberg mr816x

so…last night i changed the buffer size from 1024 to 512 and it’s running better. now i’m exclusively addressing playback and editing, not recording. how and why could this be? it’s against what little bit that i’ve learned about this. and i cannot find any good info on understanding this issue. suggested resource reading?
also, i may understand this better if i could get an answer to a question that i have yet to get a good answer for, “why would you not run playback with the highest buffer size available?”


p.s.

fyi to all you fellow newbie or soph-newbz:

here are the simple adjustments that i’ve made that i believe have had a positive effect:

  • trashed all preferences (C6, C5, CAI)
  • updated quicktime
  • updated 3rd party plugins (esp. soundtoys, which are much compatible now. they were definitely more of a strain before the updates)
  • turned ‘auto save’ off
  • turn off the airport before opening cubase
#2

Because of the size of the delay time when adjusting parameters or trying to write automation. Generally, when you adjust a parameter, you want to hear the change as close as possible to ‘real time’ so you get instant feedback on the result of your ‘tweaking.’ As a general rule you are looking for the lowest buffer size that permits running and tweaking of the plugins you choose to use.

There may be additional answers, but I think this is the basic one.

A common misunderstanding about buffer size is that it is a ‘set and forget’ process. It is perfectly reasonable to make it as low as possible for some recording task where you aren’t using cpu intensive VST/VSTis … and then later reset it as you begin to mix with them.

Why you are getting better results at 512 instead of 1024 is unclear. Increasing buffer size ensures that audio is always availble for processing in Cubase, so you don’t get those glitches. Perhaps I should ask, what you mean by “running better.”

Como

#3

hey mon. thanks for the input. what i mean is that i’m gettin fewer glitches, spikes, pop, crackles, and such. the vst esp 3rd party plugins are not making the cpu meter jump as high. ???

again, this is only concerning playback/editing/mixing…not recording. but, i wonder if the “direct monitoring” function of the mr816 has any effect on playback? whether engaged or disengaged has a pos or neg effect?

#4

I can think of no obvious reason why a lower buffer size would make things run better according to your explanation of what you mean by “running better.”

Generally, increasing buffer size is the cure for those type of problems.

There would appear to be some other problem in your set up.

I don’t know about your hardware, but simply try it engaged and then unengaged to see if it makes any difference.

You don’t have a ‘signature’ listing your computer, operating system, etc. If you add that info, someone may be able to help you.

I’ve answered your question about buffer size (I think! :slight_smile: ), but I don’t have an answer for the rest of it.

Good luck.

Como

#5

here’s what i got from a support team member:

“…every system is different and if 512 works well for you, I would suggest using that.”

a little less than satisfying.