Microsoft have just released a hotfix for Windows Vista, Windows 7 and Windows Server 2008 R2 that potentially can reduce CPU power consumption by ten percent for AMD processors, specifically ones supporting the power state C1E. This includes popular CPUs such as AMD Phenom and Athlon range of CPUs.

The hotfix can only be obtained by contacting PSS (Product Support Services) or by requesting it for instant download via the KB article below.

KB974090: An update is available that allows for a potential power saving in an AMD multicore processor that is running an x64-based version of Windows Vista SP2, of Windows Server 2008 SP2, of Windows 7, or of Windows Server 2008 R2