You set the CPU power management policy for a host using the vSphere Web Client.
Prerequisites
Verify that the BIOS settings on the host system allow the operating system to control power management (for example,
OS Controlled).
Note: Some systems have Processor Clocking Control (PCC) technology, which allows
ESXi to manage power on the host system even if the host BIOS settings do not specify OS Controlled mode. With this technology,
ESXi does not manage P-states directly. Instead, the host cooperates with the BIOS to determine the processor clock rate. HP systems that support this technology have a BIOS setting called Cooperative Power Management that is enabled by default.
If the host hardware does not allow the operating system to manage power, only the Not Supported policy is available. (On some systems, only the High Performance policy is available.)