Performance: In this question we will compare the performance of two processors using a certain benchmark. Processor L1 SizeL1 D-Cache Miss RateL1 I-Cache Miss Rate |L1 HitTime P1 P2 4KB 8KB 0 2% 2% 0.5ns 0.9ns 0 2% We are also given that accesses to the main memory takes 90ns. Additionally Processor 2 has to execute 15% more dynamic instructions than Processor 1. It is also seen that only 20% of the instructions access memory (i.e, lw and sw instructions). Profiling the code also showed us that 15% of the instructions were branch instructions. Both processors support branch prediction with 90% of the branches being predicted accurately and mis-predicts with P1 having a 1 cycle penalty and P2 having a 2 cycle penalty. Assume that we have no data hazards (a) If L1 Hit time determines the cycle time then what is the clock rate of P1 and P2? (b) Calculate how many cycles it takes to access data memory for both the processors (c) Estimate the MCPI of the benchmark for both the processors. Hint : You need to consider both instruction and data memory (d) Estimate the BCPI (Contribution due to branches) for both the processors (e) Considering just this benchmark, which of these processors is faster? (Assume Base CPI = 1.0 for both) Hint: Use execution time Performance: In this question we will compare the performance of two processors using a certain benchmark. Processor L1 SizeL1 D-Cache Miss RateL1 I-Cache Miss Rate |L1 HitTime P1 P2 4KB 8KB 0 2% 2% 0.5ns 0.9ns 0 2% We are also given that accesses to the main memory takes 90ns. Additionally Processor 2 has to execute 15% more dynamic instructions than Processor 1. It is also seen that only 20% of the instructions access memory (i.e, lw and sw instructions). Profiling the code also showed us that 15% of the instructions were branch instructions. Both processors support branch prediction with 90% of the branches being predicted accurately and mis-predicts with P1 having a 1 cycle penalty and P2 having a 2 cycle penalty. Assume that we have no data hazards (a) If L1 Hit time determines the cycle time then what is the clock rate of P1 and P2? (b) Calculate how many cycles it takes to access data memory for both the processors (c) Estimate the MCPI of the benchmark for both the processors. Hint : You need to consider both instruction and data memory (d) Estimate the BCPI (Contribution due to branches) for both the processors (e) Considering just this benchmark, which of these processors is faster? (Assume Base CPI = 1.0 for both) Hint: Use execution time
