6. [20 marks] Utility-Cost Tradeoffs A single NEC SX-9 vector processor unit (VPU) has a peak arithmetic performance of 102.4 GFs/s. The memory system supplies a peak memory bandwidth of 162 GB/s. The VPU dissipates 40 W, while the memory system dissipates 55 W. Together, both components dissipate 95 W. Every program has an arithmetic intensity (AI), measured in flops/byte, that indicates how much performance is achievable for a given bandwidth. The equation is: achievable GFs/s = min{AI*BW, peak GFs/s). a) What is the minimum AI that achieves peak arithmetic performance on an SX-9 VPU? AI = flops/byte b) What is the power efficiency of this computer system at peak performance? PE = GFs/s/W c) A special customer buys two memory systems for the one VPU, thus doubling both the bandwidth and the power of the memory. What is the new minimum AI that achieves peak arithmetic performance? AI = flops/byte d) What is the power efficiency of the new system at peak performance? PE = GFs/s/W e) Since power efficiency is a good thing, why would a customer spend more money to get less of it