Increased number of cores from 2 to 4 on VMWare VM; Windows reports "two processors"

Question

I had a VM with two cores. I powered it down and changed the settings to four cores.

Here's what I see:

System (right-click on My Computer > Properties) reports "(2 processors)"
Task Manager shows two CPU core graphs
Device manager shows four CPUs under Processors
VMWare reports four CPUs

It seems strange. Am I missing some step to get Windows to use the remaining two CPUs?

I'm running Windows 7 SP1 x64.

What EXACT version of Windows are you using? – Chopper3 Mar 05 '13 at 18:35 — Chopper3, Mar 05 '13 at 18:35
And what Edition of which Version are you running? – joeqwerty Mar 05 '13 at 18:38 — joeqwerty, Mar 05 '13 at 18:38
Windows 7 Professional SP1. – ashes999 Mar 05 '13 at 19:02 — ashes999, Mar 05 '13 at 19:02

score 4 · Accepted Answer · answered Mar 05 '13 at 19:16

4

You've give the VM 4 CPU's, Windows 7 will only deal with two physical CPUs, it'll see more but it's a client OS so only handles 2 at a time.

What you need to do is force it to think it's one CPU with four cores, by the way VMWare Workstation lets you define this on a per-VM basis as it's designed to Client OS based VMs, whereas ESXi is more focussed on the Server related OSs which can handle >2 physical CPUs.

Here's a hack/change to do what you need;

http://www.yellow-bricks.com/2009/06/04/per-processor-licenses-for-your-application/

answered Mar 05 '13 at 19:16

Chopper3

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This worked with a value of 4. – ashes999 Mar 05 '13 at 20:45
Fun fact: this also seems to be an issue in Workstation (12 at least), if you happen to try to change core number from a running VM "on the fly". `numvcpus` is increased properly, but `cpuid.coresPerSocket` doesn't get set accordingly. – mirh Mar 16 '20 at 13:03

score 2 · Answer 2 · answered Oct 07 '15 at 14:50

Most of VMware machines you will find are configured to work with the last free version of VMware Workstation, namely 6. The latter means you have 2 processors limitation. In case you have a license for VMware 6.5+ you can change "hardware compatibility" (as VMware calls it), so that you can add more processors.

score 0 · Answer 3 · answered Mar 05 '13 at 19:53

0

Also make sure you're explicitly setting it in esxi as 2cpu's 2cores each. that will be important as, like the previous poster indicated, windows 7 can't handle more than two cpu's.

answered Mar 05 '13 at 19:53

aalbertson

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Increased number of cores from 2 to 4 on VMWare VM; Windows reports "two processors"

3 Answers3