How will you calculate the maximum speed up of an application by using multiple processors in Java?

 Amdahl’s law gives the theoretical speedup in latency of the execution of a task at fixed workload.

It gives the formula to compute the theoretical maximum speed up that can be achieved by providing multiple processors to an application.

If S is the theoretical speedup then the formula is:

S(n) = 1 / (B + (1-B)/n)

where n is the number of processors

B is the fraction of the program that cannot be executed in parallel.

When n converges against infinity, the term (1-B)/n converges against zero. 

Therefore, the formula can be reduced in this special case to 1/B.

In general, the theoretical maximum speedup behaves in inverse proportion to the fraction that has to be executed serially. 

This means the lower this fraction is, the more theoretical speedup can be achieved.