Computationally efficient FDTD simulation of open-region scattering problems on the connection machine CM-5

We have developed a finite difference time domain (FDTD) code to solve large open-region scattering problems efficiently on the Connection Machine CM-5 massively parallel computer. Our approach is to use the Yee algorithm along with the anechoic chamber absorbing material boundary condition that has recently been developed. In our past experience with the CM-5, we have found that other analytical boundary conditions such as the Liao absorbing boundary condition do not parallelize well due to necessary communication operations. The core FDTD operations, on the other hand, involve very little communication since the FDTD algorithm involves only nearest-neighbor interactions within the grid. The advantage to using an absorbing material boundary condition is that it requires only a modification of the material parameters at each node and does not require any additional communication. Our benchmarks indicate that we can achieve 4.8 GFLOPS performance on a 256-node partition, a factor of 17.8 faster than the same algorithm running on a single processor of the Cray Y-MP.