Performance
The speedup of a program as a result of parallelization is given by Amdahl's law. Amdahl's Law states that potential program speedup is defined by the fraction of code (P) that can be parallelized: 1/(1-P)
If the code cannot be broken up to run over multiple processors, P = 0 and the speedup = 1 (no speedup). If it is possible to break up the code to be perfectly parallel then P = 1 and the speedup is infinite (in theory, although other factors such as scalability and complexity limit this possibility). Thus, there is an upper bound on the usefulness of adding more parallel execution units.
Gustafson's law is a law closely related to Amdahl's law but doesn’t make as many assumptions and tries to model these factors in the representation of performance. The equation can be modelled by S(P) = P − α * (P − 1) where P is the number of processors, S is the speedup, and α the non-parallelizable part of the process.
Read more about this topic: Distributed GIS
Famous quotes containing the word performance:
“When a book, any sort of book, reaches a certain intensity of artistic performance it becomes literature. That intensity may be a matter of style, situation, character, emotional tone, or idea, or half a dozen other things. It may also be a perfection of control over the movement of a story similar to the control a great pitcher has over the ball.”
—Raymond Chandler (1888–1959)
“The value of old age depends upon the person who reaches it. To some men of early performance it is useless. To others, who are late to develop, it just enables them to finish the job.”
—Thomas Hardy (1840–1928)
“No performance is worth loss of geniality. ‘Tis a cruel price we pay for certain fancy goods called fine arts and philosophy.”
—Ralph Waldo Emerson (1803–1882)