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DTSTAMP:20250822T115810Z
LOCATION:Room 5.0A52
DTSTART;TZID=Europe/Stockholm:20250616T143000
DTEND;TZID=Europe/Stockholm:20250616T150000
UID:submissions.pasc-conference.org_PASC25_sess138_msa250@linklings.com
SUMMARY:Numerical Optimization Targeting Energy-Efficient Scientific Compu
 ting
DESCRIPTION:Roman Iakymchuk (Uppsala University, Umeå University)\n\nMixed
 -precision computing has the potential to significantly reduce the cost of
  exascale computations, but determining when and how to implement it in pr
 ograms can be challenging.\nWe propose a methodology for enabling mixed-pr
 ecision with the help of computer arithmetic tools, roofline model, and co
 mputer arithmetic techniques. As case studies, we consider Nekbone, a mini
 -application for the Computational Fluid Dynamics (CFD) solver Nek5000, an
 d a modern Neko CFD application. With the help of the VerifiCarlo tool and
  computer arithmetic techniques, we introduce a strategy to address stagna
 tion issues in the preconditioned Conjugate Gradient method in Nekbone and
  apply these insights to implement a mixed-precision version of Neko. We e
 valuate the derived mixed-precision versions of these codes by combining m
 etrics in three dimensions: accuracy, time-to-solution, and energy-to-solu
 tion. Notably, mixed-precision in Nekbone reduces time-to-solution by roug
 hly 38% and energy-to-solution by 2.8x on MareNostrum 5, while in the real
 -world Neko application the gain is up to 29% in time and up to 24% in ene
 rgy, without sacrificing the accuracy.\n\nDomain: Climate, Weather, and Ea
 rth Sciences, Engineering, Computational Methods and Applied Mathematics\n
 \nSession Chair: Roman Iakymchuk (Uppsala University, Umeå University)\n\n
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