Program Execution Speed
The speed at which a digital circuit can switch states - that is, to go from "low" (VSS) to "high" (VDD) or vice versa - is proportional to the voltage differential in that circuit. Reducing the voltage means that circuits switch slower, reducing the maximum frequency at which that circuit can run. This, in turn, reduces the rate at which program instructions that can be issued, which may increase run time for program segments which are sufficiently CPU-bound.
This again highlights why dynamic voltage scaling is generally done in conjunction with dynamic frequency scaling, at least for CPUs. There are complex tradeoffs to consider, which depend on the particular system, the load presented to it, and power management goals. When quick responses are needed, clocks and voltages might be raised together. Otherwise, they may both be kept low to maximize battery life.
Read more about this topic: Dynamic Voltage Scaling
Famous quotes containing the words program, execution and/or speed:
“A candidate once called his opponent “a willful, obstinate, unsavory, obnoxious, pusillanimous, pestilential, pernicious, and perversable liar” without pausing for breath, and even his enemies removed their hats.”
—Federal Writers’ Project Of The Wor, U.S. public relief program (1935-1943)
“If Germany is to become a colonising power, all I say is, “God speed her!” She becomes our ally and partner in the execution of the great purposes of Providence for the advantage of mankind.”
—W.E. (William Ewart)
“Among the laws controlling human societies there is one more precise and clearer, it seems to me, than all the others. If men are to remain civilized or to become civilized, the art of association must develop and improve among them at the same speed as equality of conditions spreads.”
—Alexis de Tocqueville (1805–1859)