To solve this problem, we first need to develop a new and improved form of Amdahl’s
Law that can handle multiple enhancements where only one enhancement is usable at a
time. We simply change the terms involving the fraction of time an enhancement can be
used into summations:
Speedup = [ 1 – (FE1 + FE2 + FE3) + ( (FE1/SE1) + (FE2/SE2) + (FE3/SE3) ) ]‐1
If we plug in the numbers, we get:
10 = [ 1 – (0.30 + 0.30 + FE3) + ( (0.30/30) + (0.30/20) + (FE3/10) ) ]‐1
FE3 = 0.36
Therefore, the third enhancement must be usable in the enhanced system 36% of the
time to achieve an overall speedup of 10.
Grading:
3 points for correctly setting up the equation
1 points for the correct values in the equation and get the final answer.