Windows Vista and Windows Seven implement a new energy-saving technique: the core parking. 
 This technique puts in a state of deep energy saving, if supported by  the CPU, the cores not currently needed for the processing in progress. 
 Because sending in a state of energy saving and waking up a core is a  fairly slow process, the operating system must try to guess whether a  given core will be needed in the near future or not. 
 Like all forecasts, it may be wrong. 
 
 
 
howto: 
http://www.overclock...0#post_15884839