Speedup and Efficiency

• Both measure the parallelization properties of a program

  • Let T(p) be the elapsed time on p processors
  • The Speedup S(p) and the Efficiency E(p) are defined as:
  • For ideal parallel speedup we get:
  • Scalable programs remain efficient for large number of processors

S(p) = T(1)/T(p)

E(p) = S(p)/p

T(p) = T(1)/p

S(p) = T(1)/T(p) = p

E(p) = S(p)/p = 1 or 100%

Previous slide

Next slide

Back to first slide

View graphic version