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Fixed Time Model
Fixed Workload Model
Amdahl's Law revised:
Assumption: problem size fixed.
Sequential and parallelizable fraction.
Total work
W = W
s
+W
p
.
Goal: minimize computation time.
S
n
<=W
s
+ W
p
/W
s
+ W
p
/n ≤W
s
+ W
p
/W
s
= 1/f
.
Applies when there are absolute constraints for solution time
Weather prediction.
Financial transactions.
For not perfectly scalable algorithms, efficiency eventually drops to zero!
Author:
Wolfgang Schreiner
Last modification: November 8, 1996
