Here we will again use Amdahl’s law to compute speedups.
Speedup for one enhancement only = [ 1 – FE1 + (FE1/SE1) ]‐1
Speedup for two enhancements = [ 1 – (FE1 + FE2) + ( (FE1/SE1) + (FE2/SE2) ) ]‐1
If we plug in the numbers, we get:
Speedup1 = (1 – 0.15 + 0.15/30)‐1 = 1.169
Speedup2 = (1 – 0.15 + 0.15/20)‐1 = 1.166
Speedup3 = (1 – 0.70 + 0.70/10)‐1 = 2.703
Therefore, if we are allowed to select a single enhancement, we would choose E3
Speedup12 = [(1 ‐ 0.15 ‐ 0.15) + (0.15/30 + 0.15/20)]‐1 = 1.4035
Speedup13 = [(1 ‐ 0.15 ‐ 0.70) + (0.15/30 + 0.70/10)]‐1 = 4.4444
Speedup23 = [(1 ‐ 0.15 ‐ 0.70) + (0.15/20 + 0.70/10)]‐1 = 4.3956
Therefore, if two enhancements can be implemented, we would choose E1 and E3.
Grading:
2 points for correctly calculating one enhancement speedups
2 points for the correctly calculating two enhancement speedups