That is correct - the application and O/S both need to be multithreaded to take advantage of multipl vCPUs in a SMP VM - in fact if they are not you can adversely affect the performance of the VM by configuring a non-multithreaded O/S and/or application on a virtual SMP VM - this has to do with the way the VMKERNEL schedules the vCPU on the physical cores - all vCPUs are scheduled simultaneously - so it is easier to schedule a single vCPU instead of 2 or 4 vCPUs -