programperformance 3

Programperformance 3 - Program Performance Program Performance Program performance is the amount of computer memory and time needed to run a

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Program Performance
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Program Performance 2 Program Performance Program performance is the amount of computer memory and time needed to run a program How is it determined? Analytically Performance Analysis Experimentally Performance Measurement
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Program Performance 3 Why Measure Program Performance? Algorithms make up computer applications that have a great impact on humans I.e. life support systems, AEDs, grocery checkout systems, automatic teller machines
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Program Performance 4 Criteria for Measurement Time execution time usually measured by the number of instructions Space amount of memory algorithm occupies usually measured in bytes or MB How does space usage affect overall program performance?
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Program Performance 5 How to Measure Hardware should compare algorithms using consistent hardware Why? Data need to supply all runs of algorithms identical data sets Why? Time units
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Program Performance 6 Performance Analysis To analytically determine the performance of a program or an algorithm we can look at Space Complexity Time Complexity One way of expressing Space and Time Complexity is asymptotic notation .
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Program Performance 7 Space Complexity Space Complexity is defined as the amount of memory a program needs to run to completion. Why is this of concern? We could be running on a multi-user system where programs are allocated a specific amount of space. We may not have sufficient memory on our computer. There may be multiple solutions, each having different space requirements. The space complexity may define an upper bound on the data that the program can handle.
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Program Performance 8 Components of Program Space Recall a course in Computer Organization… Instruction space (Code Segment) Data space (Data Segment and Extra Segment) Environment stack space (Stack Segment) The instruction space is dependent on several factors: - the compiler that generated the machine code - the compiler options that were set at compilation time - the target computer (what’s its architecture?)
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Program Performance 9 The Data Space is also very much dependent on the computer architecture and compiler. The magnitude of the data that a program works with is another factor. Consider the following list of bytes per type:
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This note was uploaded on 03/17/2010 for the course CS 162 taught by Professor Fant during the Spring '08 term at Portland State.

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Programperformance 3 - Program Performance Program Performance Program performance is the amount of computer memory and time needed to run a

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