Low Power Server CPU Redux: Quad-Core Comes to Play
 

Since this article is focused on low power parts and that market is mostly focused on Performance/Watt, we decided we would only report results with all power management features enabled. To configure our servers with all power management features on, we perform the following:

On Intel
In the BIOS ensure that Thermal Management is On/Enabled, C1 Enhanced Mode is On/Enabled, and EIST Support is On/Enabled.

On AMD
In the BIOS ensure that PowerNow is On/Enabled. Additionally, you must install the Processor Driver, from AMD, in your OS.

http://www.anandtech.com/cpuchipsets...spx?i=3095&p=1