I did some checks.
Moving project to ssd drive from network drive speeds up audio mixdown but only few percent.
I work on a buffer 1024 and changing it to 2048 doesn’t seem to speed up the mixdown.
I think it’s the cpu. Overall CPU usage is about 35% percent, but only the first thread (CPU 0) of 12 is maxed out close to 100%…
Removing plugins, especially from izotope like mouth de-click, neutron2 or dialogue denoise speeds up the process significantly.
So the logical move would be to find a CPU that is fastest per core not to look for as many cores as possible - and according to benchmarks it’s 8700k.
Or maybe there is a way to optimise Nuendo and plugins to use all avaiable proccesing power from other threads and stick to 6850k I already have?