ALGORITHMS FOR DRIFT-DIFFUSION DEVICE SIMULATION USING MASSIVELY-PARALLEL PROCESSORS

The performance of a drift-diffusion device simulator using massively parallel processors is improved by modifying the preconditioner for th e iterative solver and by improving the initial guess for the Newton l oop. A grid-to-processor mapping scheme is presented to implement the partitioned natural ordering preconditioner on the CM-5. A new precond itioner called the block partitioned natural ordering, which may inclu de fill-ins, improves performance in terms of CPU time and convergence behavior on the CM-5. A multigrid discretization to implement a block Newton initial guess routine is observed to decrease the CPU time by a factor of two. Extensions of the initial guess routine show further reductions in the final fine grid linear iterations.