Guilin Sun
Ansys Employee
Unfortunately, 3D FDTD simulation for large object is known time-consuming, since it has to mesh everywhere, with proper mesh size or mesh accuracy. The lowest mesh accuracy is 6, meaning the mesh size if 1/6 of minimum wavelength INSIDE the material. This makes the large object more meshes so more memory,hence longer simulation.nSome people use very coarse mesh size to reduce the memory, coarser than 1/2 of the wavelength, which violates the sampling theory, will not give any physical result. even below 1/6, the accuracy is very poor, and is not recommended, except for very occasional cases.nYou can check memory requirement: nif the memory is mainly due to #1, other than use mesh accuracy 6, no other meaningful options.nif it is due to #2,it means you used too many frequency points or you have time monitors (you can disable them).nif it is due to #3, it might mean you have 3D frequency monitors.nnOne option for such device is to use DGTD, which uses finite element mesh. It can use coarser meshes for the uniform region. Please try it if you have license, or try to use the trial version.n