Windows 8 In Depth

Getting the Most Out of Your Battery

The central processing unit (CPU) chip and graphical processor unit (GPU) chip can be the two biggest energy guzzlers in a computer, but in most cases, they spend little of their time actually working. For example, as I type this chapter, my computer’s CPU takes less than a millisecond to react to each keystroke and update the display. The CPU and display processor might be occupied with useful work much less than 0.1% of the time. Processors that can take advantage of the relatively long lulls by slowing their processing speed or clock speed way down between bursts of activity significantly reduce power consumption. This extends battery life on portables (and can make desktop PCs quieter, because their CPU ...