Winn L. Rosch Hardware Bible, Sixth Edition

Power Management

With few advances in battery storage density expected in the near-term future, computer-makers have relied on reducing the power consumption of their notebook computers to extend the time a machine can operate between battery charges.

Engineers can use two basic strategies to reduce the power consumption of computers. They can design circuits and components to use less power, and they can manage the power used by the devices. Managing power needs usually means switching off whatever system components aren't being actively used. Although the two design methods can be used separately, they are generally used in tandem to shrink computer power needs as much as possible.

Microprocessors, the most power hungry of computer circuits, ...