ESXi 6.5.0 cannot see all processor's core.

[Fabiano_S]

Good Afternoon team

Issue: ESXi cannot see all processor's core.

The server has installed 2 procs model Intel(R) Xeon(R) CPU E5-2650 v4 @ 2.20GHz (12 cores).

 

The Host Summary show just 24 cores (above picture), like as this Hyperthreading feature is enabled, the correct for this is showing is 48 cores.

I've checked BIOS and all cores and Hyper-Treading is configured enabled and on the host the feature VMkernel.Boot.hyperthreading is enabled/true too.

https://docs.vmware.com/en/VMware-vSphere/6.5/com.vmware.vsphere.resmgmt.doc/GUID-4A7F14BF-8BE7-4DEF...

label = 'VMkernel.Boot.hyperthreading',
summary = 'Enable hyperthreading if available.',
key = 'VMkernel.Boot.hyperthreading',
supported = true,
defaultValue = true

Do you have some idea to resolve that?

[a_p_]

Just a guess. Maybe VMkernel.Boot.hyperthreadingMitigation has been enabled on the host!?
see https://kb.vmware.com/s/article/55806

André

[Fabiano_S]

Hi Andre,

Yes, this option is enabled it is configured as true.

key = 'VMkernel.Boot.hyperthreadingMitigation',
value = true

[a_p_ · Accepted solution]

Ok, that explains the it:

From the KB article:

Notes:

• Enabling this option will result in the vSphere UI reporting only a single logical processor per physical core, ...

André