Thanks for the log! So this is the line I was looking for:
00:00:54.851263 Changing the VM state from 'RUNNING' to 'POWERING_OFF'
This happens 54 seconds into the run. Assuming this corresponds with the test state of waiting until the log-in is finished then shutting down from within the guest, this looks like a decent speed.
From this I deduce that your host Virtualbox installation is working fine, and the issue lies with your large-provisioned guest. You could try increasing the processor and memory count in this new test guest and see if it slows down. If so, it would seem that Windows 10 either doesn't go for that much cpu & memory, or it's hard on Virtualbox to give that much to a guest.
FWIW it sounds like this project might be more suitable to bare-metal rather than virtual.
One other thing, just noticed it:
tonystark78 wrote:a Threadripper 2990WX, assigning 32 cores,
According to
https://www.amd.com/en/products/cpu/amd ... per-2990wx, this processor has 32 cores. (yes there's 64 threads, but Virtualbox doesn't use the threads, only the cores.) You have given your entire processor to the guest. Big problem. Your host has nothing to work with. This might be the cause of your slowdown. Try 30 processors in the guest, then 28, then 26, etc. until the speed is reasonable.