ESXi 5.5 VM CPU limit

[Johnnyk1]

I have a R720 with 2 sockets, 12 cores, 48 logical processors (hyper threading enabled)

I have a single VM on it, 2008 r2 ENT. I wanted to create a 40 CPU box but I'm capped at 32CPU by ESXi

why?

I've read the 5.5 compute maximums on page 3 where it states 32 cpu per core.

I'm confused about the math. Can anyone shed some light please?

[a_p_]

"Virtual CPUs per core" is the maximum overcommitment for a single physical core, i.e. you can - depending on the workload - create e.g. 32 VM's with a single vCPU per physical core.

What you want to look at in the documentation is "Virtual CPUs per virtual machine (Virtual SMP)" which is 64.

André

[a_p_]

... the maximum for the free ESXi Hypervisor is 8 vCPUs per VM.

André

[Johnnyk1]

Andre, thank you for the reply. What is stopping my VM from being more than 32 cpus?

Its the only VM on the host, Win 2008 ENT, I have 2 sockets, 12 cores, 48 logical processors

The host is ESXi Enterprise

[a_p_ · Accepted solution]

It's most likely the VM's virtual hardware version (VM Compatibility Mode) which limits you. In earlier versions, the maximum was indeed 32 vCPUs.

André

[rcporto]

What is the hardware version for the VM ? Are you using vSphere Web Client or vSphere Client (C# version) ?

[Johnnyk1]

it was the hardware version, thank you all.

I was using the web client