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Not sure why this has been flagged by a user simply because they are not reading the question, however to clarify this is being run on EXSi in a business setting and as such I believe it belongs here. I urge people to please read the question before commenting please.

I'm wondering whether running my VMWare instance with windows 7 home premium task manager is showing my usage of my entire physical core.

If I run another virtual machine on a virtual core sharing the same physical core, do both the virtual machines show the same usage, do they share the core by half and show their processor usage on half the core (assuming neither is using its full capacity) or what else is the task manager showing?

TL;DR On a virtual machine running on a virtual core, what is my task manager processor usage actually showing me?

Andrew Glazier
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It showing how much its vCPU (or virtual core) it is being used. When number of currently active/loaded vCPU is greater than the physical cores/threads provided by the host system, the various guests become showing increasing CPU load as, from their point of view, the CPU become slower.

Let do a very simplified example using an imaginary single-core host system running some single vCPU guests:

  • when running a single VM engaging the CPU at 50% load, the host system will be loaded at 50%;
  • when two guest VMs runs at 50% each, the host system will be loaded at 100%;
  • if the two guest VMs runs at 100% load, the host system can not obviously be loaded at 200%. Rather, the vCPUs exposed to the guest VMs appear slower in their operation.

In short, guest systems are time-shared based on main (real) CPU availability.

shodanshok
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  • Thanks for the answer, does this mean that, for example, if two virtual machines were sharing one physical core, while both are showing 100% usage one might actually be getting 70% 'timeshare' of the core while the other gets 30%? – Andrew Glazier Jan 16 '17 at 15:47
  • Yes, absolutely. If both VMs have the same priority, they will be close to 50% - 50%; however, by assigning different priorities, you can divide the real CPU power as you want. – shodanshok Jan 16 '17 at 15:51