Mixed-precision computing has the potential to significantly reduce the cost of exascale computations, but determining when and how to implement it in programs can be challenging. In this article, we consider Nekbone, a mini-application for the CFD solver Nek5000, as a case study, and propose a methodology for enabling mixed-precision with the help of computer arithmetic tools and roofline model. We evaluate the derived mixed-precision program by combining metrics in three dimensions: accuracy, time-to-solution, and energy-to-solution. Notably, the introduction of mixed-precision in Nekbone, reducing time-to-solution by 40.7% and energy-to-solution by 47% on 128 MPI ranks.

翻译：混合精度计算具有显著降低百亿亿次级计算成本的潜力，但在程序中确定何时以及如何实现这一技术仍具挑战性。本文以CFD求解器Nek5000的微型应用Nekbone为例，提出了一种借助计算机算术工具和屋顶线模型实现混合精度的方法。我们从三个维度（精度、求解时间和能耗）的度量组合对所推导的混合精度程序进行评估。值得注意的是，在Nekbone中引入混合精度后，在128个MPI进程上求解时间减少了40.7%，能耗降低了47%。