You set the CPU power management policy for a host using the vSphere Client.
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.)
- Browse to the host in the vSphere Client.
- Click Configure.
- Under Hardware, select Power Management and click the Edit button.
- Select a power management policy for the host and click OK.
The policy selection is saved in the host configuration and can be used again at boot time. You can change it at any time, and it does not require a server reboot.