So I've been testing a Windows 10 VM and no matter what I do, the more cores I assign to it, the slower it performs and it's pretty linear.   I have an i5-8400 with 16GB of RAM. It has 6 cores, no hyperthreading. I'm assigning 8GB to the VM and it's install on a 1TB SSD drive.   I'm testing with an Excel Macro (which is actually what I need the VM for) and here are my results (all dockers are turned off and I have no other VMs):   Without using cpu isolation for unR