Improving many flavor QCD simulations using multiple GPUs

TL;DR

This paper demonstrates how using multiple GPUs with a blocking technique and independent pseudo-fermion fields accelerates many-flavor lattice QCD simulations, achieving over 30% reduction in computation time.

Contribution

The paper introduces a blocking technique combined with multiple GPUs for efficient many-flavor dynamical QCD simulations, improving computational speed.

Findings

Achieved 34% reduction in simulation time with two GPUs.

Implemented independent pseudo-fermion fields for each flavor.

Demonstrated effectiveness for Nf=10 Wilson fermions.

Abstract

We accelerate many-flavor lattice QCD simulations using multiple GPUs. Multiple pseudo-fermion fields are introduced additively and independently for each flavor in the many-flavor HMC algorithm. Using the independence of each pseudo-fermion field and the blocking technique for the quark solver, we can assign the solver task to each GPU card. In this report we present the blocking technique for the many-flavor dynamical QCD simulations. We investigate the effect of the blocking and the acceleration with the multiple GPUs for the Schr\"{o}dinger functional simulations with Wilson SU(3) plaquette gauge action and $N_f=10$ Wilson fermions. Five pseudo-fermion fields are introduced and the quark solver task is distributed in the ratio of 2:3 to two GPUs. We expect a 40% timing reduction from the single GPU case and have observed a 34% timing reduction in the test simulations.