If you hadn’t heard, Microsoft* and Intel spent a lot of effort optimizing Windows* Server 2008 R2 (and Windows 7) to improve energy efficiency by reducing system power consumption at idle and under load.  For more details, check out the presentation from the Intel Developer Forum a few weeks ago titled Microsoft and Intel: Innovations in Hardware and Software to Help Deliver New Technology Experiences.  This presentation (and other IDF presentations) can be found at intel.com/go/idfsessions (search for SPCS003 using the session ID number).  There is good information on the operating system optimizations that were done to reduce power consumption.  Slide 22 has an excellent comparison of the power consumption of Windows Server 2003 vs. Windows Server 2008 R2 running on the same Xeon® 5500 series processors. It shows that using WinSrv2008 R2 reduced system idle and peak power consumption by ~60W!!  In addition, Hyper-V* 1.1 now uses the power management features of Intel processors to reduce power consumption during periods of low utilization.  

This is a great time to show your customers the energy efficiency benefits that come with upgrading to WinSrv2008 R2 at the same time they refresh their server infrastructure with Xeon® 5500 based servers.

*Other names and brands may be claimed as the property of others