Windows 7 Power management improvements

Microsoft has published the whitepaper “Power Management Improvements in Windows 7″ yesterday. It is made up of 14 pages that outlines some of the power management improvements that Microsoft has implemented in Windows 7 Beta.

The Windows 7 operating system provides several opportunities to decrease power consumption across the enterprise. The power management technologies in Windows 7 provide platform and processor efficiencies that reduce power consumption and can help lower energy costs. Windows 7 can also extend battery life for specific scenarios. Additionally, it provides diagnostic tools that enable OEM, IHVs, ISVs and IT pros to better manage and troubleshoot power management issues on computers and to extend the battery life for portable computers.

The list of improvements contains the following topics:
- Reduced Power Consumption
- Idle Resource Utilization
- Trigger Start Services
- Enhanced Processor Power Management
- Timer Coalescing
- Device Power Management
- Adaptive Display Brightness
- Low-Power Audio
- Bluetooth Power Improvements
- Networking Power Improvements
- Enhanced User Experiences
- Greater Enterprise Power Management
- Power Efficiency Diagnostics
- Group Policy
- Windows Management Instrumentation
- Power Policy

Interesting from a end user standpoint is the rather large paragraph outlining the enhanced user experiences:

Optimizations to key user scenarios. By focusing on the core infrastructure (as described earlier), Windows 7 enables power savings opportunities across a broad range of scenarios, including office productivity. In addition to these core infrastructure investments, Windows 7 provides power savings opportunities across specific end-user scenarios. For example, Microsoft has optimized the extended battery life during playback of standard definition content with Windows Media Player.

DVD playback is an example of a key scenario that highlights the investments made in energy efficiency in Windows 7. These optimizations span several areas, which include the following:
- Processor power management improvements that allow the processor to stay in lower performance states without impacting playback performance.
- Architectural changes that improve the Desktop Window Manager (DWM) graphics processing unit (GPU) utilization.
- Playback pipeline scaling that allows lower power operation without significantly impacting playback quality.
- Audio stack and operating system improvements that enable high-fidelity playback without requiring increased timer resolution.
- Smart data caching mechanisms that allow aggressive optical disk drive spin down.
- In addition to the focused optimizations for DVD and audio playback, Windows 7 offers additional performance optimizations across several scenarios including search, Internet browsing, and casual games. These optimizations reduce power consumption and help extend battery life.