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Speedup and Efficency Diagrams
Speedup and Efficiency
(Absolute) Speedup:
S
n
= T
s
/T
p
(n)
.
T
s
...time of sequential program.
T
p
(n)
...time of parallel program with
n
processors.
0 < S
n
<=n
(always?)
Criterium for performance of parallel program.
(Absolute) Efficiency:
E
n
= S
n
/n
.
0 < E
n
<=1
(always?)
Criterium for expenses of parallel program.
Relative
speedup and efficiency use
T
p
(1)
instead of
T
s
.
T
p
(1) >=T
s
(why?)
Relative speedup and efficiency are larger than their absolute counterparts.
Observations depend on (size of) input data.
Author:
Wolfgang Schreiner
Last modification: November 8, 1996