1.5 [4] <1.6> Consider three different processors Pl, P2, and P3 executing the same instruction set. Pl has a GHz clock rate and CPI of 15. P2 has a 2.5 GHz clock rate and CPI of 1.0. P3 has a 4.0 GHz clock rate and a CPI of 2.2. Which processor has the highest performance expressed in instructions per second? b. If the processors each execute the program in 10 seconds, find the number of cycles and the number of instructions: We are trying to reduce the execution time by 309 but this leads to an increase of 209 in the CPI. What clock rate should we have to get this time reduction?