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This paper presents our approach for applicationaware power management. We combine continuous monitoring of critical workload indicators, online power and performance model usage and timely p-state control to realize application-aware power management. We present two new power management solutions enabled by our methodology: PerformanceMaximizer (PM) finds the best possible performance under specified power constraints and PowerSave (PS) saves energy while keeping performance above specified requirements. We evaluate both using the SPEC-CPU2000 suite on a Pentium M platform discussing implications of workload characteristics and benefits of being workload-aware.

Abstract-Microarchitecturally integrated on-chip networks, or micronets, are candidates to replace busses for processor component interconnect in future processor designs. For micronets, tight coupling between processor microarchitecture and network architecture is one of the keys to improving processor performance. This paper presents the design, implementation and evaluation of the TRIPS operand network (OPN). The TRIPS OPN is a 5x5, dynamically routed, 2D mesh micronet that is integrated into the TRIPS microprocessor core. The TRIPS OPN is used for operand passing, register file I/O, and primary memory system I/O. We discuss in detail the OPN design, including the unique features that arise from its integration with the processor core, such as its connection to the execution unit's wakeup pipeline and its in flight mis-speculated traffic removal. We then evaluate the performance of the network under synthetic and realistic loads. Finally, we assess the processor performance implications of OPN design decisions with respect to the end-toend latency of OPN packets and the OPN's bandwidth.

Microprocessor performance has been improved by increasing the capacity of on-chip caches. However, the performance gain comes at the price of static energy consumption due to subthreshold leakage current in cache memory arrays. This paper compares three techniques for reducing static energy consumption in on-chip level-1 and level-2 caches. One technique employs low-leakage transistors in the memory cell. Another technique, power supply switching, can be used to turn off memory cells and discard their contents. A third alternative is dynamic threshold modulation, which places memory cells in a standby state that preserves cell contents. In our experiments, we explore the energy and performance tradeoffs of these techniques. We also investigate the sensitivity of microprocessor performance and energy consumption to additional cache latency caused by leakage-reduction techniques.