CPSC 3300 - Spring 2016
Homework 2
Due at class time on Monday, February 1
Each student must turn in a separate set of homework solutions,
but you may work together in study groups with other students
from the class. Include the names of your study group members on
the solution set you submit. (It is acceptable for the group to
prepare one document and then for each group member to turn in a
copy of that document with his or her name highlighted or circled.)
Also, please provide sufficient space on your homework solutions
so that your calculations and answers are easily readable and so
that grading will be easier. Furthermore, except for the simplest
of questions, giving only the answer without showing your work
is not acceptable. For the best chance at partial credit, show
the generic equation you are starting with and any derivations
needed to handle the information as given in the question, then
plug in the values from the question.
1. Find the execution time for a program that executes 3 billion
instructions on a processor with an avg. CPI of 2.0 and a clock
frequency of 4 GHz. (10 pts.)
2. (1.5(b) for processor P1 from textbook)
P1 has a 3.0 GHz clock rate and an average CPI of 1.5 on a given
program. If the processor executes that program in 10 seconds,
find (a) the number of cycles, and (b) the number of instructions.
(20 pts.)
3. What is the MIPS rate for processor P1 in question 2 above?
(10 pts.)
4. For the following workload and cycle values, find the average CPI.
(10 pts.)
type | freq cycles
-------+--------------
alu | 0.4 1
ld/st | 0.4 4
branch | 0.2 2
5. If a new compiler for the computer in question 4 could reduce the
number of instructions to 80% of the original total and alter the
instruction frequencies in the following manner, what would be the
total speedup? (30 pts.)
type | freq cycles
-------+--------------
alu | 0.6 1
ld/st | 0.3 4
branch | 0.1 2
6. What is the overall speedup in program execution time if an
enhancement with a speedup of 6 is available and can be used to
enhance 60% of the execution time? (10 pts.)
7. If an enhancement with a speedup of 10 is available, what fraction
of original execution time must enhanced to obtain an overall
speedup of 5? You should express the answer as a fraction rather
than a percentage. (10 pts.)