Amdahl's Efficiency

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

$\begin{eqnarray*}Amdahl's\; Efficiency=\frac{max(runtime) - avg(idling\; time\; of\; OpenMP\; threads)}{max(runtime)} \end{eqnarray*}$

where average idling time of OpenMP threads considers that threads are idling if only master thread is working and can be computed by following formula

$\begin{eqnarray*}average\; idling\; time\; of\; OpenMP\; threads=\sum_{process=0}^{num\; of\; processes} \frac{serial\; computation \cdot (number\; of\; threads\; per\; process - 1)}{number\; of\; all\; available\; threads} \end{eqnarray*}$