Not sure what this is but saving its location here so I can find it again if I need too.
In control panel (Classic View), select VAIO Control Center,Power Options
(Configure energy-saving settings on your computer)
Thermal Control Strategy:
♦ Balanced (this is selected for me)
♦ Performance Mode
♦ Silent Mode
A quick search tells me this is something to do with fan speed/cooling: http://www.google.com/search?hl=en&q=%22Thermal+Control+Strategy%22+laptop&btnG=Search&aq=f&aqi=&aql=&oq=&gs_rfai=