5. Consider two CPUs based on the same ISA (Instruction Set Architecture), namely CPU A and CPU B. CPU A's average CPI is 2.0 and CPU B's average CPI is 3.0. CPU B's clock frequency is also given as 2GHz. If CPU A is two times faster than CPU B in executing the same machine instruction sequence, what is CPU A's clock frequency? [20pts] Suppose that we are considering an enhancement that runs 10 times faster than the original machine by is usable only 50% of the time. What is the overall speedup (i.e., performance ratio) gained by incorporating the enhancement? [15pts]