Energy efficiency is one of the most active topics in modern computing today. As evidence, consider that processor and chipset vendors are marketing products on “performance per watt”, instead of just processor clock frequency and benchmark performance. Perhaps you have seen a press release for one of the many industry consortiums focused on “Green Computing”--reducing the power consumption and environmental impact of computing. Finally, battery life continues to be a major purchasing and usability factor for mobile PCs. These related energy efficiency efforts in the PC industry result in an ever-increasing interest in how Windows manages power.

In engineering Windows 7, our goal is to deliver the capabilities and features users want from a Windows PC while reducing power consumption over previous releases. Windows already provides a rich set of energy saving features, including the ability to turn off the display and automatically put the system to sleep when the user is not interacting with the computer. For Windows 7, we are building upon the investments in these areas by extending the existing capabilities and focusing on reducing power consumption when the system is idle. Although Windows is responsible for managing the power state of many devices, including the processor, hard drive and display, the remaining devices and software running on the computer have just as much (if not more) impact on power consumption and battery life. This is a challenge for everyone contributing to the PC experience.