VST Performance overloads in some projects but not others


Sometimes when I start a new project and record a single VST, most often Guitar Rig 5, I get a lot of pops and crackles. This happens only on some projects. I see that the VST Performance meter (Real Time peak) is peaking and turning red. For some reason the crackles and pops always start at around the sixth bar and get continually worse.

I’ve tried changing the buffer size but it happens even at 256. I can normally record at least a couple of VSTs at 64 before I have to increase the buffer size. I just tried opening an old project with lots of tracks and VSTs in it and it plays back fine at 256, but as soon as I change to my new project, with only one track in it, the VST performance goes through the roof.

Why does it work fine in some projects, but not others? I have the exact same settings.

My setup:

Cubase Elements 9
Windows 10
Focusrite Scarlett18i8

Thank you in advance. :slight_smile:

Are you using Guitar Rig in the older projects? Guitar Rig is a VERY processor intensive plugin, and 256 is not a “high” buffer setting by any means (I’m running a brand new iMacPro and can rarely operate at 128).