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:
“President Lowell of Harvard appealed to students ‘to prepare themselves for such services as the Governor may call upon them to render.’ Dean Greenough organized an ‘emergency committee,’ and Coach Fisher was reported by the press as having declared, ‘To hell with football if men are needed.’”
—For the State of Massachusetts, U.S. public relief program (1935-1943)
“I am gradually drifting to the opinion that this Rebellion can only be crushed finally by either the execution of all the traitors or the abolition of slavery. Crushed, I mean, so as to remove all danger of its breaking out again in the future.”
—Rutherford Birchard Hayes (1822–1893)
“Spig Wead: I’ve been thinking what a heel I’ve been about you and about my own kids. I don’t know, when I do something, I go all the way. Living. Gambling. Flying. I tap myself out. I guess that’s the way I want it to be. Maybe even the way I am.
Minne Wead: Star-spangled Spig. Damn the martinis, full speed ahead and don’t give up the ship.”
—Frank Fenton, William Wister Haines, co-scenarist, and John Ford. Spig Wead (John Wayne)