Editing Underclocking (section)

=== Smartphones and PDAs ===
Most [[smartphone]]s and [[Personal digital assistant|PDA]]s, such as the [[Motorola Droid]], [[Palm Pre]], and Apple [[iPhone]], use underclocking of a more powerful processor, rather than the full clocking of a less powerful processor, to maximize battery life. The designers for such mobile devices often discover that a slower processor gives worse battery life than a more powerful processor at a lower [[clock rate]].
They select a processor on the basis of the [[performance per watt]] of the processor.<ref>[[Wikibooks:Microprocessor Design/Performance Metrics#MIPS/mW|"Microprocessor Design: Performance Metrics"]]
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