Buffer size and crackling

UHE is now closed. For Technical Support from Ableton, please go here: http://www.ableton.com/support
Locked
Felyon
Posts: 13
Joined: Sun Jun 27, 2010 8:51 am

Buffer size and crackling

Post by Felyon » Sun Feb 26, 2012 8:54 am

Hi,

why do I get crackling and dropouts on buffer size 256 while the CPU load never exceeds 50%.
It starts crackling at 45%.
Shouldn´t this happen only near 100%?
Only 2 plugins running, RMX with 4 loops, Omnisphere with 3 slots as stack.
4 notes played on the keyboard, one finger arpeggio on lower octave (2 Omnisphere slots), 3 finger chord on higher octave (1 Omnisphere slot)

This happens with every audio device I tested.
Airport is disabled, no other running apps.

Macbook Pro C2D 2.2 GHZ
4GB Ram
MacOS 10.6.8
Studiolive 16.0.2

cotdagoo
Posts: 1030
Joined: Fri Oct 26, 2007 5:34 pm
Location: canuhduh

Re: Buffer size and crackling

Post by cotdagoo » Mon Feb 27, 2012 3:15 pm

Hi,

That's precisely why the CPU Usage Simulator is located at the bottom of the Audio configuration window..

You simulate high cpu usage and adjust the buffer and other settings while listening to a tone that's generated until you can get the results you desire or require to get audio playback without crackling.

Don't have Omnisphere, but pretty sure it's a pretty heavy footprint as far as VSTs go in terms of CPU/Memory use.

Generally a lower buffer will require more CPU power and less latency (time between hitting a key and audio outputting).. If you can deal with higher latency, increase your buffer to take some of the strain off your CPU.

lyovino
Posts: 509
Joined: Thu May 27, 2010 3:29 am

Re: Buffer size and crackling

Post by lyovino » Mon Feb 27, 2012 5:04 pm

Felyon wrote:Hi,

why do I get crackling and dropouts on buffer size 256 while the CPU load never exceeds 50%.
It starts crackling at 45%.
Shouldn´t this happen only near 100%?

4GB Ram
MacOS 10.6.8
I recently moved to Lion and have been experiencing the same as you describe.
The Simulator seems to be running oddly. If I raise the load and put the buffers up, then apply it, now it allows me to go backwards
and get a lower latency settings. I thought I was alone on this one?

As for Omnisphere, you might consider upping your RAM. A lot of patches included are fierce on your ram.. Love it though!
iMac, Intel Core i7, 2.8 GHz, 16GB
Yosemite, Live 9.xx Suite (64- bit)
Push, Apogee Ensemble

Locked