Homework P&H Ch. 1
Answer the following questions about Patterson and Hennessy, Chapter 1.
You only need to turn in those that have a point count assigned.
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(1 point)
What are the five classical components of a computer?
What does each one do?
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(1 point)
Which of the following have exhibited exponential improvement over the
past few decades?
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transistor density
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memory capacity
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memory access time
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disk storage capacity
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disk access time
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Why has processor clock speed not increased in the past few years?
What have processor manufacturers done to compensate for this?
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(1 point)
Improvements in a processor lead to a reduction in execution time for
a program from 7 seconds to 5 seconds.
What is the percentage improvement for performance?
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What are the two current SPEC benchmark suites for processor
performance?
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Which of the factors in the performance equation are most likely to be
affected by the following changes to a processor?
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Adding more powerful instructions
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Improvements in transistor technology
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Large scale reorganizations, such as pipelining
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(1 point)
In a certain processor, 20% of the executed instructions are branches
and jumps, 20% are loads and stores, and 60% are arithmetic and
logical instructions.
Branches and jumps execute in 3 cycles, loads and stores execute in 5
cycles, and arithmetic and logical operations execute in 4 cycles.
What is the effective CPI?
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If you were a computer architect, how would you obtain the percentages
in the previous problem?
How would you obtain the cycle counts for the different types of
instructions?
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(1 point)
An incremental modification of the above processor reduces the cycle
count for arithmetic and logical instructions from 4 cycles to 3
cycles.
This modification increases the cycle time by 10%.
No new instructions are added so the instruction count is unchanged.
What is the overall percentage improvement in performance?
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(1 point)
The current version of a processor spends 45% of its time on
arithmetic and logic instructions, 30% on loads and stores, and
25% on branches.
Modifications to the circuitry improve performance on loads and stores
by 50% and performance on branches by 25%.
The performance on arithmetic and logic instructions is unchanged.
What is the overall performance improvement, expressed as a
percentage?