The Essentials Of Computer Organization And Architecture 4th Edition by Linda Null,Julia Lobur

Exercise 72

Amdahl's Law is as applicable to software as it is to hardware. An oft-cited programming truism states that a program spends 90% of its time executing 10% of its code. Thus, tuning a small amount of program code can often have an enormous effect on the overall performance of a software product. Determine the overall system speedup if:
a) 90% of a program is made to run 10 times as fast (900% faster).
b) 80% of a program is made to run 20% faster.