Consider two different implementations, P1 and P2, of the same instruction set architecture. There are four classes of instructions (Compute, Load, Store, and Branch) in this instruction set. The clock rate and CPI of each class is given below. Clock rate CPI-Compute CPI-Load CPI-Store CPI-Branch
P1 1.0 GHz 1 5 4 2
P2 2.0 GHz 2 3 3 4
1. Assume that a program has 1-million (106) instructions that is divided into the four classes as follows: 50% Compute, 30% Load, 10% Store and 10% Branch, which implementation is faster? .
2. What is the global CPI for each implementation?
3. Find the clock cycles required in both cases.
The following table shows the number of instructions for a program.
Arith Store Load Branch Total
500 50 100 50 700
4. Assuming that arith instructions take I cycle, load and store 5 cycles and branch 2 cycles, what is the execution time of the program in a 2 GHz processor?
5. Find the CPI for the program.
6. If the number of load instructions can be rcduced by one-half, what is the speed-up and the CPI?