System-level design methods can provide a systematic and effective way of evaluating various design options, thus shortening the product development time. This paper relaxes the HC algorithm by considering the K best candidates in each clustering iteration to alleviate the possibility of being trapped in local minimum during hardware/software (HW/SW) partition. We also present an architecture mapping algorithm together with the defined sensitivity measure to further reduce the hardware requirement. Simulation results show that the complexity of exploration time can be greatly reduced with only little performance loss as compared to the exhaustive search. The proposed algorithm can thus provide a good compromise between exploration time and accuracy.