Amdahl's Law examples

Amdahl's Law states that the maximal speedup of a computation where the fraction S of the computation must be done sequentially going from a 1 processor system to an N processor system is at most

                 1 / (S + [(1 - S) / N])

Does anyone know of books or notes where the actual analysis of the code, for some non-trivial computation, for determining the fraction S is done ?