Diff for "AmdahlsLaw" - Dr. A's Wiki

Differences between revisions 16 and 31 (spanning 15 versions)

<<latex( $S p e e d u p = \frac{P e r f o r m a n c e u s i n g e n h a n c e m e n t w h e n p o s s i b l e}{P e r f o r m a n c e w i t h o u t e n h a n c e m e n t}$ )>>

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( $S p e e d u p O v e r a l l = \frac{O l d E x e c u t i o n T i m e}{N e w E x e c u t i o n T i m e}$ )>> (1)

This gives a new Execution time of

<<latex( $N e w E x e c T i m e = O l d E x e c T i m e (1 - F r a c t i o n E n h a n c e d + \frac{F r a c t i o n E n h a n c e d}{S p e e d u p E n h a n c e d})$ )>>

So we have

<<latex( $S p e e d u p O v e r a l l = (\frac{1}{1 - F r a c t i o n E n h a n c e d + \frac{F r a c t i o n E n h a n c e d}{S p e e d u p E n h a n c e d}})$ )>>

Back to ComputerTerms

-  ⇤ ← Revision 16 as of 2005-06-27 22:25:12 → 
  Size: 1107
  Editor: yakko
  Comment:
+   ← 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.
 Line 3:
-{{{#!latex2
 $S p e e d u p = \frac{P e r f o r m a n c e u s i n g e n h a n c e m e n t w h e n p o s s i b l e}{P e r f o r m a n c e w i t h o u t e n h a n c e m e n t}$ 
}}}
+<<latex( $S p e e d u p = \frac{P e r f o r m a n c e u s i n g e n h a n c e m e n t w h e n p o s s i b l e}{P e r f o r m a n c e w i t h o u t e n h a n c e m e n t}$ )>>
-Line 11:
+Line 9:
-{{{#!latex2
 $S p e e d u p O v e r a l l = \frac{O l d E x e c u t i o n T i m e}{N e w E x e c u t i o n T i m e}$ 
}}}
+<<latex( $S p e e d u p O v e r a l l = \frac{O l d E x e c u t i o n T i m e}{N e w E x e c u t i o n T i m e}$ )>> (1)
-Line 15:
+Line 11:
+This gives a new Execution time of
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+Line 13:
-{{{#!latex2
 $N e w E x e c T i m e = O l d E x e c T i m e (1 - F r a c t i o n E n h a n c e d + \frac{F r a c t i o n E n h a n c e d}{S p e e d u p E n h a n c e d})$ 
}}}

{{{
or

                       Execution Time affected by Improvement
New Execution Time =   --------------------------------------  + Execution Time unaffected
                            Amount of Improvement (x times)
+<<latex( $N e w E x e c T i m e = O l d E x e c T i m e (1 - F r a c t i o n E n h a n c e d + \frac{F r a c t i o n E n h a n c e d}{S p e e d u p E n h a n c e d})$ )>>
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+Line 16:
-
SpeedupOverall = --------------------------------------------
                                           FractionEnhanced
                 (1 - FractionEnhanced) + ------------------ )
                                           SpeedupEnhanced
-Line 34:
+Line 17:
-}}}
+<<latex( $S p e e d u p O v e r a l l = (\frac{1}{1 - F r a c t i o n E n h a n c e d + \frac{F r a c t i o n E n h a n c e d}{S p e e d u p E n h a n c e d}})$ )>>