Diff for "AmdahlsLaw"

Differences between revisions 10 and 13 (spanning 3 versions)

\begin{equation} \label{eq:speedup}
   Speedup = \frac{Performance~using~enhancement~when~possible}{Performance~without~enhancement}
\end{equation}

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:

\begin{equation}
   SpeedupOverall = \frac{Old~Execution~Time}{New~Execution~Time}
\end{equation}
\begin{equation}
   New~Exec~Time = Old~Exec~Time \left( 1 - FractionEnhanced + \frac{FractionEnhanced}{SpeedupEnhanced}\right)
\end{equation}

                                                                    FractionEnhanced
New Execution Time = Old Execution Time ( (1 - FractionEnhanced) + ------------------ )
                                                                    SpeedupEnhanced

or

                       Execution Time affected by Improvement
New Execution Time =   --------------------------------------  + Execution Time unaffected
                            Amount of Improvement (x times) 

So we have
                                     1
SpeedupOverall = --------------------------------------------
                                           FractionEnhanced
                 (1 - FractionEnhanced) + ------------------ )
                                           SpeedupEnhanced

Back to ComputerTerms

-  ⇤ ← Revision 10 as of 2005-06-27 22:18:06 → 
  Size: 1591
  Editor: yakko
  Comment:
+   ← Revision 13 as of 2005-06-27 22:22:36 → ⇥
  Size: 1467
  Editor: yakko
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
 Line 5:
-   Speedup = \frac{Performance~for~entire~task~using~the~enhancement~when~possible}{Performance~for~entire~task~without~enhancement}
+   Speedup = \frac{Performance~using~enhancement~when~possible}{Performance~without~enhancement}
 Line 7:
-}}}


{{{
           Performance for entire task using the enhancement when possible
Speedup = -----------------------------------------------------------------
              Performance for entire taks without using the enhancement
-Line 20:
+Line 13:
+{{{#!latex2
\begin{equation}
   SpeedupOverall = \frac{Old~Execution~Time}{New~Execution~Time}
\end{equation}
\begin{equation}
   New~Exec~Time = Old~Exec~Time \left( 1 - FractionEnhanced + \frac{FractionEnhanced}{SpeedupEnhanced}\right)
\end{equation}
}}}
-Line 21:
+Line 23:
-                  Old Execution Time
SpeedupOverall = --------------------
                  New Execution Time