With XFdtd EM Simulation Software, there is no limit to the resources you can exploit to solve your EM calculations. We often are asked, “How can I allocate resources to obtain the fastest simulation?” or, “What are the performance advantages of hardware X over hardware Y?” This report quantifies the performance profile of XFdtd’s GPU and MPI technologies. By running approximately 160 simulations on NVIDIA’s PSG Cluster, we demonstrate the pros and cons of different combinations of equipment and techniques, including cost considerations for those researching available hardware.