Discrete ordinates SN transport solvers on unstructured meshes pose a challenge to scale due to complex data dependencies, memory access patterns and a high-dimensional domain. In this paper, we review the performance bottlenecks within the shared memory parallelization scheme of an existing transport solver on modern many-core architectures with high core counts. With this analysis, we then survey the performance of this solver across a variety of compute hardware. We then present a new Asynchronous Many-Task (AMT) algorithm for shared memory parallelism, present results showing an increase in computational performance over the existing method, and evaluate why performance is improved.
@article{arxiv.2510.11513,
title = {An Asynchronous Many-Task Algorithm for Unstructured $S_{N}$ Transport on Shared Memory Systems},
author = {Alex Elwood and Tom Deakin and Justin Lovegrove and Chris Nelson},
journal= {arXiv preprint arXiv:2510.11513},
year = {2025}
}