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:
“If the worker and his boss enjoy the same television program and visit the same resort places, if the typist is as attractively made up as the daughter of her employer, if the Negro owns a Cadillac, if they all read the same newspaper, then this assimilation indicates not the disappearance of classes, but the extent to which the needs and satisfactions that serve the preservation of the Establishment are shared by the underlying population.”
—Herbert Marcuse (1898–1979)
“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)
“The correct rate of speed in innovating changes in long-standing social customs has not yet been determined by even the most expert of the experts. Personally I am beginning to think there is more danger in lagging than in speeding up cultural change to keep pace with mechanical change.”
—Mary Barnett Gilson (1877–?)