CSRC COLLOQUIUM ON SCIENTIFIC FRONTIERS AND FORUM ON COMPUTATIONAL SCIENCE  AT THE EXTREME SCALE
*Presentations of 2016 ACM Gordon Bell Prize Winner and Finalist*

In 2016, six outstanding research efforts in high performance technical computing were selected as finalists in supercomputing's most prestigious competition, the ACM Gordon Bell Prize in High Performance Computing. "High performance computing continues to underwrite the progress of research using computational methods for the analysis and modeling of complex phenomena," according to a statement by ACM Award Committee co-chairs. "This year's finalists illustrate the key role that high performance computing plays in 21st Century research. The Gordon Bell Award committee has worked diligently to select from many choices, those most deserving of recognition for this year". The year 2016 also marked a special year with three of these finalists from China, a historical breakthrough, and the prize was finally awarded to the team lead by Dr.Chao Yang.

About Two Speakers
Dr. Chao Yang, the lead author of 2016 ACM Gordon Bell prize winner, is a professor and the vice director of the Laboratory of Parallel Software and Computational Sciences, Institute of Software, Chinese Academy Sciences and a professor at the State Key Laboratory of Computer Science, Chinese Academy Sciences. He has published over 40 papers in peer-reviewed journals and conferences including SISC, JCP, TC, SC, PPoPP and IPDPS. His research interests include numerical analysis and modeling, large-scale scientific computing, and parallel numerical software. He is a member of IEEE, ACM and SIAM.

Dr. Jian Zhang, the lead author of a 2016 ACM Gordon Bell prize finalist, received Ph.D. in Applied Mathematics from the University of Minnesota (USA) in 2005. He was a postdoc in the department of Mathematics Pennsylvania State University before joining the Computer Network Information Center, Chinese Academy of Sciences in July 2009, where he is currently an associate professor. He has published over 40 journal and conference papers in scientific computing, parallel computing, computational material science and computer visualization.

1) Chao Yang: 10M-Core Scalable Fully-Implicit Solver for Nonhydrostatic Atmospheric Dynamics

An ultra-scalable fully-implicit solver is developed for stiff time-dependent problems arising from the hyperbolic conservation laws in nonhydrostatic atmospheric dynamics. In the solver, we propose a highly efficient hybrid multigrid domain decomposition preconditioner that can greatly accelerate the convergence of the solver at the extreme scale. For solving the overlapped subdomain problems, a physics-based multi-block a synchronized incomplete LU factorization method is customized to further exploit the on-chip fine-grained concurrency. We perform systematic optimizations on different hardware levels to achieve best utilization of the heterogeneous computing units and a substantial reduction of data movement costs. The fully-implicit solver enables fast and accurate atmospheric simulations on the new Sunway TaihuLight supercomputer in China, scaling to over ten million heterogeneous cores and achieving a sustained performance of over two petaflops.

2) Jian Zhang: Extreme-Scale Phase Field Simulations of Coarsening Dynamics on the Sunway TaihuLight Supercomputer

Many important properties of materials such as strength, ductility, hardness, and conductivity are determined by the microstructures of the material. During the formation of these microstructures, grain coarsening plays an important role. The Cahn-Hilliard equation has been applied extensively to simulate the coarsening kinetics of a two-phase microstructure. It is well accepted that the limited capabilities in conducting large scale, long time simulations constitute bottlenecks in predicting microstructure evolution based on the phase field approach. We present here a scalable time integration algorithm with large step-sizes and its efficient implementation on the Sunway TaihuLight supercomputer. The highly nonlinear and severely stiff Cahn-Hilliard equations with degenerate mobility for microstructure evolution are solved at extreme scale, demonstrating that the latest advent of high performance computing platform and the new advances in algorithm design are now offering us the possibility to simulate the coarsening dynamics accurately at unprecedented spatial and time scales.