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Revision 8 as of 2005-06-27 22:16:45
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Revision 32 as of 2020-01-23 23:15:20
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Deletions are marked like this. Additions are marked like this.
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{{{#!latex2
\begin{equation}
   Speedup = \frac{Performance~for~entire~task~using~the~enhancement~when~possible}{Performance~for~entire~task~without~enhancement}
\end(equation}
}}}

Hello

{{{
           Performance for entire task using the enhancement when possible
Speedup = -----------------------------------------------------------------
              Performance for entire taks without using the enhancement
}}}
Speedup=Performance using enhancement when possiblePerformance without enhancement
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{{{
                  Old Execution Time
SpeedupOverall = --------------------
                  New Execution Time
SpeedupOverall=Old Execution TimeNew Execution Time
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                                                                    FractionEnhanced
New Execution Time = Old Execution Time ( (1 - FractionEnhanced) + ------------------ )
                                                                    SpeedupEnhanced
This gives a new Execution time of
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or

                       Execution Time affected by Improvement
New Execution Time = -------------------------------------- + Execution Time unaffected
                            Amount of Improvement (x times)
New Exec Time=Old Exec Time(1FractionEnhanced+FractionEnhancedSpeedupEnhanced)
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                                     1
SpeedupOverall = --------------------------------------------
                                           FractionEnhanced
                 (1 - FractionEnhanced) + ------------------ )
                                           SpeedupEnhanced
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}}} SpeedupOverall=(11FractionEnhanced+FractionEnhancedSpeedupEnhanced)

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Speedup=Performance using enhancement when possiblePerformance without enhancement

See SpeedUp

Notice that we are talking about the entire task here and that performance (speedup) is defined in terms of execution time! So we have to define the following:

SpeedupOverall=Old Execution TimeNew Execution Time

This gives a new Execution time of

New Exec Time=Old Exec Time(1FractionEnhanced+FractionEnhancedSpeedupEnhanced)

So we have

SpeedupOverall=(11FractionEnhanced+FractionEnhancedSpeedupEnhanced)

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AmdahlsLaw (last edited 2020-01-23 23:15:20 by 68)