How To Configure Hyperthreaded Core Sharing in the vSphere Web Client
You can select how the virtual CPUs of a virtual machine share physical cores on a hyperthreaded system.
Hyperthreading technology allows a single physical processor to behave like two logical processors.
Although hyperthreading does not double the performance of a system, it can increase performance by better utilizing idle resources.
The hyperthreaded core sharing option must be enabled in your system’s BIOS settings.
VM must be Power off
Select a virtual machine.
In the VM Hardware panel, click Edit Settings.
Click Virtual Hardware.
Click the CPU triangle to expand the CPU options.
In the HT Sharing drop-down menu, select a sharing mode.
The virtual CPUs of this virtual machine can share cores with other virtual CPUs of this or other virtual machines.
The virtual CPUs of this virtual machine have exclusive use of a processor core whenever they are scheduled to it. The other hyperthread of the core is halted while this virtual machine is using the core
On a virtual machine with exactly two virtual processors, the two virtual processors are allowed to share one physical core (at the discretion of the host scheduler), but this virtual machine never shares a core with any other virtual machine. If this virtual machine has any other number of processors other than two, this setting is the same as the None setting.