Linear and superlinear speedup in parallel FDTD processing

The nature of the FDTD method is that simulation of big and complicated passive microwave circuits and large antenna models requires a vast amount of computer operational memory and run-time. The relevance of fast parallel processing in the FDTD method proves to be significant and in most cases is performed on distributed memory (DM) machines using MPI library. We will focus on two main aspects: speedup efficiency optimization to achieve linear scaling with a number of CPUs (N), and importance of having proper parallel solution for both shared memory (SM) and distributed memory (DM) systems. Under some specific, but realistic circumstances, it is possible to achieve superlinear speedup - with efficiency far over 100%.