Speedup

Evolution according to Amdahl's law of the theoretical speedup in latency of the execution of a program in function of the number of processors executing it, for different values of p. The speedup is limited by the serial part of the program.

Amdahl's law is often used in parallel computing to predict the theoretical speedup when using multiple processors.

By summer the Americans were sending 10,000 fresh men a day to the Western Front, a speedup made possible by leaving their equipment behind and using British and French munitions.

However even given infinitely fast dependency checking logic on an otherwise conventional superscalar CPU, if the instruction stream itself has many dependencies, this would also limit the possible speedup.

However, even quadratic speedup is considerable when N is large.

Indeed, often there is a trade-off between the running time and the number of computers: the problem can be solved faster if there are more computers running in parallel (see speedup ).

Metrics that are inversely proportional to time (speedup, IPC ) should be averaged using the harmonic mean.

No mathematical proof has been found that shows that an equally fast classical algorithm cannot be discovered, although this is considered unlikely. citation For some problems, quantum computers offer a polynomial speedup.

Some commercial PAL region releases exhibit this same problem and, therefore, can be played in NTSC systems without issue while others will face a 20% speedup if played in an NTSC console.

Speedup in a serial program Assume that a task has two independent parts, A and B. Part B takes roughly 25% of the time of the whole computation.

This will make the computation much faster than by optimizing part B, even though part B's speedup is greater by ratio, (5 times versus 2 times).