GPU-Based Conjugate Gradient Solver for Lattice QCD with Domain-Wall Fermions

TL;DR

This paper introduces the first GPU-accelerated conjugate gradient solver tailored for lattice QCD with domain-wall fermions, significantly speeding up a key computational bottleneck in unquenched simulations.

Contribution

It presents a novel GPU-based CG solver for 5D DWF operators, optimized with mixed-precision, preconditioning, and CUDA techniques, achieving high computational performance.

Findings

Achieves 180/233 Gflops on GTX 285/480

Reduces computation time in lattice QCD simulations

Demonstrates effective GPU acceleration for DWF operators

Abstract

We present the first GPU-based conjugate gradient (CG) solver for lattice QCD with domain-wall fermions (DWF). It is well-known that CG is the most time-consuming part in the Hybrid Monte Carlo simulation of unquenched lattice QCD, which becomes even more computational demanding for lattice QCD with exact chiral symmetry. We have designed a CG solver for the general 5-dimensional DWF operator on NVIDIA CUDA architecture with mixed-precision, using the defect correction as well as the reliable updates algorithms. We optimize our computation by even-odd preconditioning in the 4D space-time lattice, plus several innovative techniques for CUDA kernels. For NVIDIA GeForce GTX 285/480, our CG solver attains 180/233 Gflops (sustained).