Multi-Precision Solvers for Non-Linear Systems on AMR Grids*

Modern hardware designed for high performance computing has become increasingly heterogeneous in an effort to increase peak performance and decrease power usage. One of the trends in recent hardware has been the introduction of specialized compute units for which peak performance can only be achieved with reduced precision arithmetic (i.e. Tensor Cores in the NVIDIA A-100 GPU). Historically, flow calculations have relied exclusively on double precision floating point arithmetic and its unclear how much of a flow solver infrastructure can be moved to reduced precision without significantly compromising accuracy. In this work, we will address this question by utilizing iterative refinement and progressive precision to develop multi-precision solvers for non-linear systems on multi-level grids stemming from adaptive mesh refinement.