Power dissipation has become an important consideration for processor designs. Assessing power using simulators is problematic given the long runtimes of real applications. Researchers have responded with techniques to reduce the total number of simulated instructions while still maintaining representative simulation behavior. Synthetic testcases have been shown to reduce the number of necessary instructions significantly while still achieving accurate performance results for many workload characteristics. In this paper, we show that the synthetic testcases can rapidly and accurately assess the dynamic power dissipation of real programs. Synthetic versions of the SPEC2000 and STREAM benchmarks can predict the total power per cycle to within 6.8% error on average, with a maximum of 15% error, and total power per instruction to within 4.4% error. In addition, for many design changes for which IPC and power change significantly, the synthetic testcases show small errors, many less than 5%. We also show that simulated power dissipation for both applications and synthetics correlates well with the IPCs of the real programs, often giving a correlation coefficient greater than 0.9.