Visio-c4-3ed-amdahl - Department of Computer Science
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Transcript of Visio-c4-3ed-amdahl - Department of Computer Science
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.25 .50 .75 1.0
f=Fraction of time doing fp operations
Speed-up
Amount of improvement in FP operations = 5
execution time
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KEY QUESTION: Suppose the MFP executes 3x108
instructions when it runs the BMP. How many instructions does the MNFP execute?
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MFP Extime = IC/(MIPS x 106) = 300x106/27.6x106 = 11 secs
MNFP Extime = 2760x106/50x106 = 55.2 secs.
MIPS can be a flawed/misleading performance measure
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5.38 on page 339,
CPI=(.21)(5)+(.12)(4)+(.46)(4)+(.21)(3)
CPI=(.21)(5)+(.12)(4)+(.46)(4)+(.21)(3)
