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VMWare, changing CPUs

I have a 2 socket Intel machine with 8 cores per socket

For experimentation purposes, I want to run the most cores as possible on the VM

The Edit Settings of my VM under CPUs has the following CPUs set

Number of virtual sockets:     1

Number of cores per socket:    1

Total number of cores:         1

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How can I set this to configure to push the maximum amount of cores possible to the VM

Does a single vCPU or core have to be left for the hypervisor ?
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Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
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Commented:
The Maximum number of vCPUs you can add to a VM, is dependant upon your license.

The Max could be 8 CPUs.

But you need to make sure your host OS is licensed to support those CPUs.
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
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Commented:
See here for Processor Guides in Windows OS

http://support.microsoft.com/kb/888732
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
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What vSphere license do you have?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
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Commented:
the maximum number of CPUs you will be able to allocate based on licensing is 8. Unless you have Enterprise Plus, and you could allocate 32.

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Commented:
So if I get the Enterprise plus, Could I assign 16 cores, or would I have to save one for the Hypervisor
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
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you could assign 32 CPUs to a VM.

But you still need to have the correct Windows license, for Windows to be able to use them all, otherwise the processors will NOT be used.
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
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Commented:
the hypervisor reserves processor usage for itself. so you will be able to allocate all.

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Commented:
you could assign 32 CPUs to a VM.

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So On a 16 core machine, I can allocate 32 vCPU

Is that because Intel is double threaded?
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
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Commented:
that would depend on how many physical cores, physical processors, hyperthreading you havevavailable on the physical host.

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Commented:
On a 2 socket, 16 core (8 core per socket)  machine with Hyper-threading enabled, how many vCPU's can I allocate
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
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Commented:
in the summary page what does it state?

?? x CPUs?

and does your VM Guest OS support 32 processors?

Author

Commented:
The Host summary says I have 16 CPUS, and the guest OS (RHEL) can support 16 or 32 Cores)

So does that mean the most I can assign to this machine is 16 vCPU (or can I assign 32 since the cores are double threaded)
Andrew Hancock (VMware vExpert / EE Fellow)VMware and Virtualization Consultant
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Commented:
16 vCPUs
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