This paper presents a technique for high-level power estimation of microprocessors. The technique, which is based on abstract execution profiles called ‘event signatures’, operates at a higher level of abstraction than commonly-used instruction-set simulator (ISS) based power estimation methods and should thus be capable of achieving good evaluation performance. As a consequence, the technique can be very useful in the context of early system-level design space exploration. In this paper, we also compare our power estimation results to those from the instruction-level simulators Wattch and Sim-Panalyzer. In these experiments, we demonstrate that with a good underlying power model, the signature-based power modeling technique can yield accurate estimations (a mean error of 3.1% compared to Wattch in our experiments). At the same time, our signature-based power modeling technique is at least an order of magnitude faster than the simulations performed by Wattch or Sim-Panalyzer.