CPU difference ESXi host vrs VM

You can see difference between CPU usage MHz of HostSystem = ESX server and CPU usage MHz of Virtual Machine.
It is about metric CPU usagemhz which gets different results on Host and VM.

Definition

• VM - Amount of actively used virtual CPU.
  This is the host's view of the CPU usage, not the guest operating system view.
• Host - Sum of the actively used CPU of all powered on virtual machines on a host.
  The maximum possible value is the frequency of the processors multiplied by the number of processors.

Explanation:

• VM usagemhz is usage of virtual CPUs.
• Host usagemhz is real number means real computing power usage of real server (Host).

It is possible and it is usual case to have more virtual CPUs (together from all VM residing on a Host) than real cores (even logical) on a Host.

New processors can have Hyper threding and it is up to VM application if it can use effectively more threads.
If it is the case then this VM's usagemhz can be higher than total Host's usagemhz.
The NUMA and other new processor features make the situation with "usagemhz" more difficult.
VM usagemhz is good for comparing VMs.