CSCI 370 Computer Architecture: Homework 1

CSCI 370 Computer Architecture: Homework 1

Due date: On or before Thursday, February 13, 2025
Absolutely no copying others’ works

Name: ______________________

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(60% total) Consider two different implementations of the same instruction set architecture. The instructions can be divided into three classes according to their CPI (class A, B, and C). The clock rate and CPI of each implementation are given in the following table:

Clock rate CPI Class A CPI Class B CPI Class C

P1 3.0 GHz 3 2 2

P2 3.5 GHz 4 3 2
1. (30%) Given a program with a dynamic instruction count of 10⁵ instructions divided into classes as follows: 30% class A, 40% class B, and 30% Class C, which implementation is faster?
  ^†Hint: You have to find the execution times.
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2. (15%) What is the global CPI for each implementation?
  ^†Hint: global CPI = execution time × clock rate ÷ number of instructions, where the execution time can be found from the solution of the previous question.
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3. (15%) Find the clock cycles required in both cases.
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(40% total) The following table shows the results of the SPEC CPU2006 bzip2 benchmark running on an AMD Barcelona:

Instruction Count×10⁹ Execution Time (seconds) Reference Time (seconds)

1800 600 5000
1. (15%) Find the CPI if the clock cycle time is 0.25 ns.
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2. (10%) Find the SPECratio.
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3. (15%) Find the increase in CPU time if the number of instructions of the benchmark is increased by 20% without affecting the CPI.
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