Fayoum University Faculty of Engineering Electrical Engineering Dep.

ECE 204 B 2nd year comm. Spring 2014

11-

Sheet # 1 (Performance)

Problem #1

Consider two different machines; with two different instruction sets have a clock

rate of 200 MHz. The following measurements are recorded on the two machines

running a given set of benchmark programs:

Instruction Type Instruction Count

(millions)

Cycles per

Instruction

Machine A

Arithmetic and logic

Load and store

Branch

Others

8

4

2

4

1

2

3

4

Machine B

Arithmetic and logic

Load and store

Branch

Others

10

8

2

4

1

2

3

4

1- Determine the effective (average) CPI, MIPS rate, and execution time for

each machine.

2- Comment on the results.

Problem #2

Consider two different implementations of the same instruction sets architecture.

There four classes of instructions A, B, C and D. The data clock rate and CPI for

each implementation are given in the following table:

Clock rate CPI Class A CPI Class B CPI Class C CPI Class D

P1 1.5 GHz 1 2 3 4

P2 2 GHz 2 2 2 2

Given a program with 106 instructions divided into classes as following: 10%

class A, 20% class B, 50% class C and 20% class D.

1- What is average CPI for each implementation?

2- Find the clock cycles required in both cases?

3- Which implementation is faster? Show your calculations

Fayoum University Faculty of Engineering Electrical Engineering Dep.

ECE 204 B 2nd year comm. Spring 2014

21-

Problem #3

Assuming that arithmetic instructions take 1 cycle, load and store 5 cycles, and

branches 2 cycles

Arith Store Load Branch Total

650 100 600 50 1400

1- What is the execution time of the program in a 2 GHz processor?

2- Find the CPI for the program.

3- If the number of load instructions can be reduced by one half, what is the

speedup and the CPI?

Problem #4

The following table shows the execution time (ms) of five routines of a program:

Routine A Routine B Routine C Routine D Routine E

12 45 6 36 3

1- Find the total execution time and by how much it is reduced if the time of

routines A, C, and E is improved by 15%.

2- How much is the total time reduced if routine B is improved by 10%?

3- How much is the total time reduced if routine D is improved by 10%?