Amdahls Law Who What When Where Why and
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Amdahl’s Law – Who, What, When, Where, Why - - and How !! CDA 3101 – Spring 2016 – Review for Quiz 5 Contents: • What is Amdahl’s Law? Who was Gene Amdahl? • What Kinds of Problems Do We Solve With Amdahl’s Law? • How Do We Solve These Amdahl’s Law Problems? USE UP AND DOWN ARROW KEYS TO NAVIGATE ANIMATIONS
What is Amdahl’s Law? Amdahl's law is an expression used to find the maximum expected improvement S to an overall system when only part of the system (f. E) is improved by a factor f. I. Amdahl’s Law is often used in parallel computing to predict theoretical maximum speedup using multiple processors. (https: //en. wikipedia. org/wiki/Amdahl%27 s_law ) Why Do We Use Amdahl’s Law? è ESTIMATE SYSTEM PERFORMANCE for… è Performance Improvement Problems!!
Who Was Gene Amdahl? Gene Myron Amdahl (November 16, 1922 – November 10, 2015) was an American computer architect and high-tech entrepreneur, chiefly known for his work on mainframe computers at IBM and later his own companies, especially Amdahl Corporation. He formulated Amdahl's Law… (https: //en. wikipedia. org/wiki/Gene_Amdahl )
What Kinds of Problems Do We Solve With Amdahl’s Law? è Performance Improvement Problems!! Entire System Part of System That Can’t Be Improved Part That Can Be Improved f. E IMPROVEMENT Time T for part of system that can’t be improved Time TE for f. E with improvement Time TO for f. E without improvement f I = TO / TE
How Do We Solve Amdahl’s Law Problems? Amdahl’s Law Equation: (S) (f. E) Divide Problem Space Into Three Cases: 1. Given: f. E and f. I 2. Given: S and f. E 3. Given: S and f. I Find: S Find: f. I Find: f. E (f. I)
How Do We Solve Amdahl’s Law Problems? Case 1: Given: f. E and f. I Find: S
How Do We Solve Amdahl’s Law Problems? Case 2: Given: S and f. E Find: f. I Oops, that one didn’t work so well … let’s try another example
How Do We Solve Amdahl’s Law Problems? Case 2: Given: S and f. E Find: f. I
How Do We Solve Amdahl’s Law Problems? Case 3: Given: S and f. I Find: f. E
That’s All There Is To It!! Have Fun Surfing with Amdahl’s Law!!