Consider two different implementations, M1 and M2, of the same instruction set. There are three classes of instructions (A, B, and C) in the instruction set. M1 has a clock rate of 2.0GHz and M2 has a clock rate of 2.5GHz. The average number of cycles for each instruction class and their frequencies (for a typical program) are as follows:

Instruction Class. M1-Cycles/Instruction Class. M2 -Cycles/Instruction Class. Frequency

A 1 2 60% B 3 2 30% C 4 3 10%

1. (a) Calculate the average CPI for each machine, M1, and M2.

2. (b) Calculate the average MIPS ratings for each machine, M1 and M2.

3. (c) Which machine has a smaller MIPS rating? Which individual instruction class CPI do you need to change, and by how

   much, to have this machine have the same or better performance as the machine with the higher MIPS rating (you can only change the CPI for one of the instruction classes on the slower machine)?