How to measure a computer performance ?

2. Suppose we have a program runs in 100 seconds on a computer, and the

multiplication subroutine takes 40 seconds. If we want the program to run 30% faster,

how many seconds do we have to improve the multiplication subroutine ?

3. There are 2 computers. Computer A clock cycle time is 350ps, CPI is 3. Computer B

clock cycle time is 400ps, CPI is 2.5. Which computer runs faster on same program ?

4. There are 3 instructions types A B C, each instruction type CPI is A:4, B:2, C:3. If we

have two programs, program 1 has 2 of A type instructions, 3 of B type instructions,

4 of C type instructions; program 2 has 3 of A type instructions, 4 of B type instruction,

3 C type instruction. Which program runs faster on the same computer ?

5. Why does the computer microprocessor vendors switch to multi-processors ?

6. What are the software factors which will affect the program

performance ?