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:
“In former years it was said that at three o’clock in the afternoon all sober persons were rounded up and herded off the grounds, as undesirable. The tradition of insobriety is still carefully preserved.”
—For the State of Vermont, U.S. public relief program (1935-1943)
“I will soon be going out to shape all the singing tomorrows.”
—Gabriel Péri, French Communist leader. Letter, July 1942, written shortly before his execution by the Germans. Quoted in New York Times (April 11, 1943)
“The greatest felony in the news business today is to be behind, or to miss a big story. So speed and quantity substitute for thoroughness and quality, for accuracy and context. The pressure to compete, the fear somebody else will make the splash first, creates a frenzied environment in which a blizzard of information is presented and serious questions may not be raised.”
—Carl Bernstein (b. 1944)