Amdahl's Efficiency

Amdahl's Efficiency indicates serial computation and can be computed as follows:

$\begin{eqnarray*}Amdahl's\; Efficiency=\frac{avg( computation\; time) }{avg( time\; in\; useful\; computation\; within\; OpenMP ) + avg( serial\; computation )} \end{eqnarray*}$

Where average serial computation computed as weighted arithmetic mean. If number of threads is equal across processes average serial computation can be computed as ordinary arithmetic mean.