Differences between revisions 30 and 31
Revision 30 as of 2008-10-24 02:23:46
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Revision 31 as of 2008-10-24 02:24:20
Size: 720
Editor: 209-142-131-35
Comment:
Deletions are marked like this. Additions are marked like this.
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[[latex($$SpeedupOverall = \frac{Old~Execution~Time}{New~Execution~Time}$$)]] (1) <<latex($$SpeedupOverall = \frac{Old~Execution~Time}{New~Execution~Time}$$)>> (1)
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[[latex($$New~Exec~Time = Old~Exec~Time \left( 1 - FractionEnhanced + \frac{FractionEnhanced}{SpeedupEnhanced}\right)$$)]] <<latex($$New~Exec~Time = Old~Exec~Time \left( 1 - FractionEnhanced + \frac{FractionEnhanced}{SpeedupEnhanced}\right)$$)>>
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[[latex($$SpeedupOverall=\left(\frac{1}{1-FractionEnhanced + \frac{FractionEnhanced}{SpeedupEnhanced}}\right)$$)]] <<latex($$SpeedupOverall=\left(\frac{1}{1-FractionEnhanced + \frac{FractionEnhanced}{SpeedupEnhanced}}\right)$$)>>

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<<latex($$Speedup = \frac{Performance~using~enhancement~when~possible}{Performance~without~enhancement}$$)>>

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:

<<latex($$SpeedupOverall = \frac{Old~Execution~Time}{New~Execution~Time}$$)>> (1)

This gives a new Execution time of

<<latex($$New~Exec~Time = Old~Exec~Time \left( 1 - FractionEnhanced + \frac{FractionEnhanced}{SpeedupEnhanced}\right)$$)>>

So we have

<<latex($$SpeedupOverall=\left(\frac{1}{1-FractionEnhanced + \frac{FractionEnhanced}{SpeedupEnhanced}}\right)$$)>>

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