In this paper, we will propose several different data and instruction cache configurations and analyze their power as well as performance implications on the processor. Unlike most existing work in low power microprocessor design, we explore a high performance processor with the latest innovations for performance. Using a detailed, architectural-level simulator, we evaluate full system performance using several different power/performance sensitive cache configurations. We then use the information obtained from the simulator to calculate the energy consumption of the memory hierarchy of the system. Based on the results obtained from these simulations, we will determine the general characteristics of each cache configuration. We will also make recommendations on how best to balance power and performance tradeoffs in memory hierarchy design. 1 Introduction In this paper we will concentrate on reducing the energy demands of an ultra high-performance processor, such as the Pentium Pro or..