As Frontier, the world’s first exascale supercomputer, was being assembled at the Oak Ridge Leadership Computing Facility in 2021, understanding its performance on mixed-precision calculations remained a difficult prospect. That gap in understanding wasn’t an oversight but rather a sign of just how novel supercomputer systems that excel at mixed precision remain in computational science, which has been dominated by double precision–focused systems for almost its entire history.As Frontier, the world’s first exascale supercomputer, was being assembled at the Oak Ridge Leadership Computing Facility in 2021, understanding its performance on mixed-precision calculations remained a difficult prospect. That gap in understanding wasn’t an oversight but rather a sign of just how novel supercomputer systems that excel at mixed precision remain in computational science, which has been dominated by double precision–focused systems for almost its entire history.[#item_full_content]