The purpose of this work is to analyze and measure the performance of a heterogeneous Beowulf cluster used for human head SAR FDTD simulation, whose solution demands a great computational power. This work presents and discusses some techniques to improve the computational power with low economic cost. The performance results were excellent, strongly suggesting the adoption of this technology for more demanding and detailed human head SAR simulations. Furthermore, the present implementation can be taken into account in the development of efficient largescale wave electromagnetic simulators based on parallel and distributed computation. © 2005 IEEE.