I get very confusing suggestions from different individuals on YouTube.
I guess a better way to put it is, "What absolutely needs to be on the system drive?
What you should preface your question with is, product list you own, computer specs and specifically what size your system drive is and crucially how much free space you have thereon.
NI states the apps themselves (and in a few cases some content which is of a minimal size) are installed on the internal/system drive (Kontakt, Reaktor, Battery, Absynth etc.) The libraries can optionally be put on externals.
