Power Settings in XenServer 6.5: C-states, Turbo and CPU Frequency Scaling

Power Settings in XenServer 6.5: C-states, Turbo and CPU Frequency Scaling

http://support.citrix.com/article/CTX200390

This article explains changes introduced in XenServer 6.5 to the handling of power settings and describes how users with specific needs can change the configuration.
XenServer's default power settings are optimal for most users, so do not normally need to be modified.
In its default configuration, XenServer 6.5:
* uses all available C-states regardless of BIOS settings,
* uses the "performance" CPU frequency governor for Intel processors and the more power-friendly "ondemand" CPU frequency governor for AMD processors, and
* uses frequency scaling and Turbo mode as controlled by the BIOS settings.
It is recommended to use XenServer's default configuration and to enable OS-controlled frequency scaling and Turbo mode in the BIOS.

えー C-statesの設定戻すのめんどくさい。

ちなみに、XenServer6.2SP1以前は、C-states はDisable推奨というか必須だったはず。