This has happened a few times now.

I work on something adding various vst instruments, I notice crackling and I only see one core being used in the CPU meter.

I save, close Sonar and re-open the project, and the CPU meter shows multiple cores used and the crackling has gone.

It's not a big deal as it usually only happens if I start a totally blank project (Working on a template setup for example) and add vsts one at a time, opening templates where everything is already in place it never seems to happen.

Is this a quirk of some vsts or a Sonar thing? (All my vst/vsti's are 64bit)