Hi all,
 
I've just added a Scarlett 18i20 and noticed that if I run it at a buffer size of 16 at 48KHz the CPU performance meters in SONAR disappear.
 
Increasing the buffer to 32 or greater and they come back.
 
Anyone else see this?

64 buffer size is considered ultra-low by most here and not even achievable by many.
 
16 is likely stressing your system way too hard.  You should find the "sweet spot" and not push it that low just because you can.
 
By all means, report it to Focusrite, but if there's no problem at 32 buffer and above, I honestly wouldn't sweat it.

Yes, I lose Perf Meter bars at 16 samples. Light projects play fine at that buffer size, but anything that spikes DPC latency is likely to cause a dropout and I can hear the CPU working overtime so I almost never run it that low.

My guess it is the buffer processing is so fast there is nothing to display. From http://www.cakewalk.com/D...elp=ControlBar.11.html

CPU meters. Displays the time it takes to process a buffer full of audio data as a percentage of the maximum time available to process that data and maintain uninterrupted playback.

I'm Superconducting!
 
This is without any VST instruments running, just streaming in audio from SPDIF and a few effects.
 

scook
My guess it is the buffer processing is so fast there is nothing to display. From http://www.cakewalk.com/D...elp=ControlBar.11.html

CPU meters. Displays the time it takes to process a buffer full of audio data as a percentage of the maximum time available to process that data and maintain uninterrupted playback.

My guess is that with a buffer being processed every 333us there isn't enough time for the process that calculates the height of the bars to complete, and the variables that store the height of each bar are just staying at their initialized value of 0. That or it was just coded to skip the Perf Meter routine when the buffer is set below 32 samples because it's not feasible to deliver meaningful values.