4. (10 points) Consider two different implementations of the same MIPS instruction set architecture. The instructions can be divided into three classes according to their CPI (Rtype, I-type, J-type). P1 with a clock rate of 2.8GHz and CPIs of 1,3,3; and P2 with a clock rate of 3.5GHz and CPIs of 2,3 , and 2 . Given a program with a dynamic instruction count of 3.0E6 instructions divided into classes as follows: 50% R-type, 25\% I-type, 25%J-type, which implementation is faster and by how much? a. What is the global CPI for each implementation? b. Find the clock cycles required in both cases