When parallelizing an application, the ideal speedup is speeding up by the number of processors. This is limited by two things: percentage of the application that can be parallelized and the cost of communication. Amdahl's Law takes into account the former but not the latter.

a$.$ What is the speedup with $N$ processors if $80\%$ of the application is parallelizable, ignoring the cost of communication?

b$.$ What is the speedup with eight processor if$,$ for every processor added, the communication overhead is $0\mathrm{.}5\%$ of the original execution time.