Battery life is one of the most important issues notebook users face. Notebooks now come with built-in functions to extend battery life, such as throttling CPU speed when the system is idle or managing the speed of the CPU fan. Most notebooks also come with manufacturer-provided power-management software—a utility that works in conjunction with Windows' own power functions to extend battery life by dynamically changing power consumption as needed.
If you're not happy with the power-management software provided by your notebook maker or by what's provided in Windows by default, a program called SpeedswitchXP might fit the bill. It allows the user to set power-consumption behaviors for the system based on whether the system is running on wall current or battery power.
The program comes configured with four "policies," or behaviors, for how to manage the CPU: maximum performance, battery-optimized, maximum battery and dynamic switching. The program creates a new power scheme specifically for itself in the Power Options section of the Control Panel, and uses that to assume control over power management.
The program's basic options are reminiscent of the Power Options section -- timeouts for the display, hard drive, when to enter standby or hibernation, etc. However, its more advanced functions allow for some more elaborate configuration, such as how to set user, machine and CPU power-policy controls. By default these should not be changed, but if you're familiar with how Windows deals with power states (Quick, what's the difference between the S3 and S4 power states?), you can edit them to get even more precise control over how power is managed.
The program is free and has source code included as well.
About the author: Serdar Yegulalp is editor of the Windows Power Users Newsletter, which is devoted to hints, tips, tricks, news and goodies for Windows NT, Windows 2000 and Windows XP users and administrators. He has more than 10 years of Windows experience under his belt, and contributes regularly to SearchWinComputing.com and SearchSQLServer.com.
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