...

• Suppose instead that while 99% of the sequential execution time can be improved using parallelism, these remains 1% which cannot be parallelised (why might this happen?)

• Recall Amdahl's law: overall speedup is given by
  
  $$\begin{eqnarray*}\frac{1} {(1 - {\rm fraction}_{\rm enhanced}) + \frac{{\rm fra... ...\\ = \frac{1}{1-0.99 + 0.99/100} = \frac{1}{0.0199} \\ = 50 \end{eqnarray*}$$