Performance is emphasized with CPU virtualization, and therefore will run on available processors when possible. The virtual machines use the underlying physical resources and only use the virtualization layer to run instructions when necessary so that the virtual machines continue to run as though directly accessing physical server hardware. A virtual machine can be configured with up to 128 virtual CPUs (vCPUs) as of vSphere 6.
Keep in mind that a virtual machine cannot have more vCPUs than logical CPUs available on the ESXi host. A logical CPU (LCPU) is a physical core, unless hyperthreading is enabled, at which point there are two logical CPUs per core. The VMkernel includes a CPU scheduler that dynamically schedules vCPUs on the ESXi host's physical processor.
The CPU scheduler can use each logical processor independently to execute VMs, providing capabilities similar to traditional Symmetric Multi-Processing (SMP) systems. Symmetric multiprocessing is simply...