Question

Using Amdahl’s Law, calculate the speedup gain of an application that has a 60 percent parallel component for (a) two processing cores and (b) four processing cores.

Answer 1

Answer:

a) Speedup gain is 1.428 times.

b) Speedup gain is 1.81 times.

Explanation:

in order to calculate the speedup again of an application that has a 60 percent parallel component using Anklahls Law is speedup which state that:

$t=\frac{1 }{(S + (1- S)/N) }$

Where S is the portion of the application that must be performed serially, and N is the number of processing cores.

(a) For N = 2 processing cores, and a 60%, then S = 40% or 0.4

Thus, the speedup is:

$t = \frac{1}{(0.4 + (1-0.4)/2)} =1428671$

Speedup gain is 1.428 times.

(b) For N = 4 processing cores and a 60%, then S = 40% or 0.4

Thus, the speedup is:

$t=\frac{1}{(0.4 + (1-0.4)/4)} = 1.8181$

Speedup gain is 1.81 times.