Guests see Cores as Cores or Separate CPUs?

[gavinscott]

If I install a Windows 7 guest under ESXi 3.7 Update 4, will I be able to get it to user four CPU cores (out of the eight in my two E5520s), or does ESXi make each core look like a separate CPU, in which case if Windows 7 is limited to two CPUs then I would not be able to get more than two cores effectively allocated to it?

Thanks,

G.

[weinstein5 · Accepted solution]

Each core will be seen by the guest o/s as a seperate cpu - so if you assign two virtual cpus to a vm than they will run on two cores -

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[Troy_Clavell]

correct, each VM will be limited to their maximum configuration. They will be treated a separate CPU, not cores.

Hope that makes sense

[gavinscott]

Thanks. Seems like this behavior rather screws anyone using software that is licensed per-CPU.

G.

[mcowger]

Many software vendors have licensing provisions to deal with this.

--Matt

VCP, vExpert, Unix Geek

[weinstein5]

As pointed out the ISV's do deal with this usually by licensing to virtual cpu - so a vm with a single virtual cpu will be licensed for one cpu even though it might be running on an 8 CPU quad core box -

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[gavinscott]

Yes, but I'd like to use something licensed for two CPUs that would be happy to use 4 or 8 cores on those CPUs, such as any of the workstation versions of Windows, or computer-intensive software packages that are also license limited by CPU but not by core.

G.