Back with this, sorry
Something weird is going on.
The scene is rather large, so it makes sense it takes a while. (quite some instances)
I have disabled all update stuff, because except for moving objects and camera's nothing special happens.
A frame renders in roughly 7-8 seconds, but WAITING takes around 50 seconds now. (rendering with F10)
Updating scene is only displayed for barely one second.
When WAITING is displayed, layout shows not responding in Taskmanager.
Rendering each frame manually with f9 is a few seconds quicker somehow.
Also, somehow it WAS quick (was able to do 3 or 4 frames / minute, but suddenly it has dropped to one frame/minute (7 seconds really doing something usefull)
It must be something in this scene, but I have no idea why it was first ' quick' and now really crawls.
System is CPU = i9 -9820k, 64GB RAM, 2x 2080ti, 2x 1080ti and a bunch of NVME drives where the data is stored/written to.