Microsoft recently released a new 14-page whitepaper entitled “Windows 7 Power Management” to outline the power management technologies in Windows 7 that reduce power consumption. For those curious as to how exactly Windows 7 will use less power, this is your answer. For those who just want the quick scoop, here are 8 different ways how Windows 7 mainly save battery life:
1) Idle Resource Utilization
This is one of the most important power management technologies because idle time is a significant portion of the time a computer is turned on. Idle efficiency in Windows 7 is improved by reducing resource utilization and enabling hardware to go into lower power states during long periods of inactivity. This includes the processor, disk, memory, and network activity on the computer. To demonstrate just how much power can be saved, CPUs consume nearly 0 watts when idle, but up to 35 watts at full power.
2) Trigger Start Services
Services were usually started automatically right after startup and would run in the background waiting for an event to occur. In Windows 7, certain services are only started when triggered by an event such as device insertion or an IP change. This makes it unnecessary to have services starting all the time and reduces the amount of background processes.
3) Enhanced Processor Power Management
Windows 7 will include device driver support for the latest PPM technologies. PPM allows Windows 7 to choose the appropriate processor performance state depending on the load and scale performance accordingly.
4) Adaptive Display Brightness
Microsoft says that the average display is set to turn off after 10-15 minutes of inactivity. Often times however, there are shorter periods of inactivity in between. To save additional power, ADB defines will allow dimming the display. ADB can also utilize hardware sensor technology to adjust display brightness accordingly to ambient light.
5) Low-Power Audio
Windows 7 will support the latest Intel HD Audio low-power specification, which introduces a new power state known as D3Cold. This is the lowest unresponsive power state that a codec can go into. It can also further conserve power when an audio device is not in use. Windows 7 also supports selective suspend technology that extends to USB audio-class devices such as microphones and web-cams.