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

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. Timing comparisons for large scale systems utilizing multiple GPUs at a

variety of precisions will be presented.