Differences between revisions 1 and 29 (spanning 28 versions)
Revision 1 as of 2004-01-25 18:20:24
Size: 301
Editor: yakko
Comment:
Revision 29 as of 2008-10-24 02:23:30
Size: 720
Editor: 209-142-131-35
Comment:
Deletions are marked like this. Additions are marked like this.
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{{{
           Performance for entire task using the enhancement when possible
Speedup = -----------------------------------------------------------------
              Performance for entire taks without using the enhancement
}}}
[[latex($$Speedup = \frac{Performance~using~enhancement~when~possible}{Performance~without~enhancement}$$)]]
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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($$SpeedupOverall=\left(\frac{1}{1-FractionEnhanced + \frac{FractionEnhanced}{SpeedupEnhanced}}\right)$$)]]

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