Even though there is plenty in NX which is multithreaded for our purposes, I leave hyperthreading off on all our workstation because NX is not written to use hyperthreading.
Update,
I just found the docs pertaining to hyperthreading...
Hyper-Threading on Intel Processors
Some Intel processors provide a Hyper-Threading feature in which a single processor can support multiple instructions, thus emulating additional processor cores. When Hyper-Threading is enabled, it can lead to a conflict with threading within NX Nastran for both SMP and DMP executables. Hyper-Threading should be disabled, which can be done permanently through BIOS operations.
11.0.2