VM CPU Usage in GHz more then configured CPU resources for VM

[mattpoe]

Hi,

I have a VM with 2 sockets and 16 cores per socket (total of 32 cores). At peak times, the applications running inside the VM will use as much CPU resources as they can get (due to an application bug ...).

When this happens, I have observed that vCenter will display ~94GHz of total CPU usage for the VM and here comes my question. The VM only has 32 cores and the CPUs installed in the host only run at 2,4 GHz. Therefore I would have expected the total displayed usage at around 76,8 GHz but not at 94 GHz:

Can somebody explain to me why vCenter is reporting a usage of around 94 Ghz?

Cheers,

Matt

[daphnissov]

The difference is probably due to overhead incurred by ESXi to run a VM in this state. The hypervisor requires resources of its own for different schedulers, so what's displayed is a sum of VM guest proper and hypervisor overhead.

[mattpoe]

Thanks for your reply. I was also thinking about that. I'm just wondering that the difference is around 17GHz.