I probably have the same problem.
Very slow boot when doing pass-through and much memory.
First pinned cpu is working 100%
Will try 6.7 soon, but this has been a problem since at least 2016 so I don't have any expectations.
Same as Craig, let me know if any logs or other info is needed.
And just to confirm. (Since I did not find anything about vm-x)
vm-x is Virtual Machine extensions?
Also known as x86 virtualization?
Or as unraid is reporting on System Profiler for the CPU, VME (Virtual mode extension)?
Ref: https://en.wikipedia.org/wiki/VMX
So if your cpu has VT-x (Intel) or AMD-V (AMD, doh) this would work?
\John