Disaggregated Design for GPU-Based Volumetric Data Structures

Abstract: Volumetric data structures are traditionally optimized for data locality, with a primary focus on efficient memory access patterns in computational tasks. However, prioritizing data locality alone can overlook other critical factors necessary for optimal performance, e.g., occupancy, communication, and kernel fusion. We propose a novel disaggregated design approach that rebalances the trade-offs between data locality and these essential objectives. This includes reducing communication overhead in distributed memory architectures, mitigating the impact of register pressure in complex boundary conditions for fluid simulation, and increasing opportunities for kernel fusion. We present a comprehensive analysis of the benefits of our disaggregated design, applied to a fluid solver based on the Lattice Boltzmann Method (LBM) and deployed on a single-node multi-GPU system. Our evaluation spans various discretizations, ranging from dense to block-sparse and multi-resolution representations, highlighting the flexibility and efficiency of the disaggregated design across diverse use cases. Leveraging the disaggregated design, we showcase how we target different optimization objectives that result in up to a $3\times$ speedup compared to state-of-the-art solutions.