We present TEM²P²EST, a flexible, cycle-accurate microarchitectural power/performance analysis tool based on SimpleScalar. The goal was to build a “flexible” simulation tool, incorporating several estimation models and providing a scalable framework for future development. This approach is based on the fact that different power models have different tradeoffs in terms of power estimation accuracy and flexibility/scalability. The simulator generates power estimates based on either empirical data or analytical models. In future, other modes like estimation based on RTL extraction can be included. The tool includes analytical models for dynamic and leakage power, di/dt power, dual V_t support and process technology scaling options. It has a thermal model built to study thermal issues and techniques like clock throttling. Initial studies show that our results are consistent and match well with real design simulated with SPICE. In addition, we validated our temperature model with measurement on a typical microprocessor heat solution.