QUOKKA Code Achieves GPU-Accelerated Particle-Mesh Interactions

The study presents a novel, GPU-optimized algorithm for particle-mesh interactions in grid-based hydrodynamics simulations, implemented in the QUOKKA code. The algorithm is designed for massively parallel architectures and overcomes the inefficiency of particle neighbor searches across multiple GPU nodes by using a new 'particle-mesh-particle' interaction scheme. The algorithm proceeds in two main stages: first, quantities exchanged between particles and the mesh are deposited into a buffer mesh equipped with ghost zones. In the second stage, the buffer states are applied to real mesh states, incorporating cell-wise limiters to enforce physical constraints. The algorithm is implemented in the GPU-native radiation-magnetohydrodynamics code QUOKKA and validated through a comprehensive suite of tests. The results show that the algorithm achieves approximately 50% weak-scaling efficiency running on up to 8192 GPUs on the Frontier supercomputer. This scheme enables efficient, scalable particle-mesh coupling for GPU-optimized simulations of star formation and feedback in galaxies. Future research should focus on optimizing the algorithm for different hardware architectures and exploring its application to other astrophysical problems. The development of this algorithm represents a significant step towards improving the efficiency and scalability of GPU-accelerated simulations in astrophysics.

_Context: This intelligence report was compiled by the DailyOrbitalWire Strategy Engine. Verified for Art. 50 Compliance._