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Norman, Matthew R

Publications and source records attributed to Norman, Matthew R.

A WENO-Limited, ADER-DT, Finite-Volume Scheme for Efficient, Robust, and Communication-Avoiding Multi-Dimensional Transport

The novel ADER-DT time discretization is applied to two-dimensional transport in a quadrature-free, WENO- and FCT-limited, Finite-Volume context. Emphasis is placed on (1) the serial and parallel computational properties of ADER-DT and this framework and (2) the flexibility of ADER-DT and this framework in efficiently balancing accuracy with other constraints important to transport applications. This study demonstrates a range of choices for the user when approaching their specific application while maintaining good parallel properties. In this method, genuine multi-dimensionality, single-step and single-stage time stepping, strict positivity, and a flexible range of limiting are all achieved with only one parallel synchronization and data exchange per time step. In terms of parallel data transfers per simulated time interval, this improves upon multi-stage time stepping and post-hoc filtering techniques such as hyperdiffusion. This method is evaluated with standard transport test cases over a range of limiting options to demonstrate quantitatively and qualitatively what a user should expect when employing this method in their application.

Norman, Matthew R↗

Targeting Atmospheric Simulation Algorithms for Large Distributed Memory GPU Accelerated Computers

Computing platforms are increasingly moving to accelerated architectures, and here we deal particularly with GPUs. In [15], a method was developed for atmospheric simulation to improve efficiency on large distributed memory machines by reducing communication demand and increasing the time step. Here, we improve upon this method to further target GPU accelerated platforms by reducing GPU memory accesses, removing a synchronization point, and better clustering computations. The modification ran over two times faster in some cases even though more computations were required, demonstrating the merit of improving memory handling on the GPU. Furthermore, we discover that the modification also has a near 100% hit rate in fast on-chip L1 cache and discuss the reasons for this. In concluding, we remark on further potential improvements to GPU efficiency.

atmospheric simulation↗