Refine your search�ソスF     
Report No.
 - 

Development of exascale full-f gyrokinetic simulation on Summit and FUGAKU

Idomura, Yasuhiro   

The Gyrokinetic Toroidal 5D full-f Eulerian code GT5D is based on a semi-implicit finite difference scheme, in which a stiff linear 4D convection operator is subject to implicit time integration, and the implicit finite difference solver for fast kinetic electrons occupies more than 80% of the total computing cost. The implicit solver was originally developed using a Krylov subspace method, in which global collective communications and halo data communications were becoming bottlenecks on the latest accelerator based platforms. To resolve this issue, the convergence property is improved by using a new FP16 preconditioner, and an order of magnitude reduction of the number of iterations and thus, communications was achieved. A communication-avoiding (CA) solver based on the FP16 preconditioner was developed by utilizing the new support for FP16 SIMD operations on FUGAKU, and was ported also on Summit. The new CA solver showed significant speedups both on FUGAKU and SUMMIT, and its performance portability was demonstrated.

Accesses

:

- Accesses

InCites™

:

Altmetrics

:

[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.