Application-driven processor design exploration for power-performance trade-off analysis

This paper presents an efficient design exploration environment for high-end core processors. The heart of the proposed design exploration framework is a two-level simulation engine that combines detailed simulation for critical portions of the code with fast profiling for the rest. Our two-level simulation methodology relies on the inherent clustered structure of application programs and is completely general and applicable to any microarchitectural power/performance simulation engine. The proposed simulation methodology is 3-17/spl times/ faster, while being sufficiently accurate (within 5%) when compared to the fully detailed simulator The design exploration environment is able to vary different microarchitectural configurations and find the optimal one as far as energy/spl times/delay product is concerned in a matter of minutes. The parameters that are found to affect drastically the core processor power/performance metrics are issue width, instruction window size, and pipeline depth, along with correlated clock frequency. For very high-end configurations for which balanced pipelining, may not be possible, opportunities for running faster stages at lower voltage exist. In such cases, by using up to 3 voltage levels, the energy/spl times/delay product is reduced by 23-30% when compared to the single voltage implementation.