"I understand you run NX-D on Windows 10 in a virtual machine on an 8core system?"
No. NX-D on a physical machine Win7, 32 GB RAM, 8core i7, all SSD-based. NX-D is horribly slow, many times slower than Photo Ninja, the latter being glacial enough. Photoshop and other software fly at super speed thus the machine itself is fully operational and there is nothing wrong with the system as such.
In fact, over the years, I have never had any installation of Nikon Capture, Capture2, or NX-d, that wasn't glacially slow. This on many different hardware configurations.