Using Dynamic Voltage and Frequency Scaling (DVFS) for Power Management (1037164)

Purpose

This article provides best practices to use Dynamic Voltage and Frequency Scaling (DVFS) for Power Management feature in ESX/ESXi hosts.

 

Dynamic Voltage and Frequency Scaling (DVFS) is a vSphere  feature that allows your ESX/ESXi host to dynamically switch its CPU frequency depending on the current load on the host. This saves power by providing only the voltage and frequency required to sustain the host and the virtual machines on the host.

Resolution

ESX/ESXi 4.0  

To set the CPU power management policy in ESX/ESXi 4.0, use the advanced host attribute Power.CpuPolicy. This attribute setting is saved in the host configuration and can be used again at boot time. This attribute can be changed at any time and does not require a server reboot.

For more information on configuring DVFS, see the CPU Power Management section of the vSphere Resource Management Guide. 

ESX/ESXi 4.1
You can set the CPU power management policy for a ESX/ESXi 4.1 host using the vSphere Client.

Note: ESX/ESXi supports the Enhanced Intel SpeedStep and Enhanced AMD PowerNow! CPU power management technologies. For the VMkernel to take advantage of the power management capabilities provided by these technologies, you must enable power management, called Demand-Based Switching (DBS), in the BIOS.

 

To set the CPU power management policy:

1. In the vSphere Client inventory panel, select a host and click the Configuration tab.
2. Under Hardware, click Power Management and then click Properties.
3. 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 does not require a server reboot.

For more information, see the Using CPU Power Management Policies section of the vSphere Resource Management Guide.

Source:-

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1037164