Most USB devices don’t need to draw power the entire time they’re plugged in. With this setting enabled, the drivers controlling the ports that know which peripherals and devices aren’t needed can shut each one off individually to conserve battery power. The amount saved depends on what you have plugged into the ports.
Windows includes device driver support that allows a notebook to determine the optimal power performance state depending on the tasks it’s running. By setting the minimum processor state, you allow for a range of usage that can save on battery life if the computer isn’t engaged in taxing activities such as playing video or soaring over Google Earth. Even at the default setting—5 percent—your notebook won’t slow the processor if you need the juice. You can set a lower maximum processor state to glean more battery life from your system.
Page 2: Sleep and Hibernation Settings
Page 3: USB Settings and Processor Power Management
Page 4: Display and Multimedia Settings
Page 5: Battery Settings