Multi-mass solvers for lattice QCD on GPUs

Graphical Processing Units (GPUs) are more and more frequently used for lattice QCD calculations. Lattice studies often require computing the quark propagators for several masses. These systems can be solved using multi-shift solvers but these algorithms are memory intensive which limits the size of the problem that can be solved using GPUs. In this paper, we show how to efficiently use a memory-lean single-mass solver to solve multi-mass problems. We focus on the BiCGstab algorithm for Wilson fermions and show that the single-mass solver not only requires less memory but also outperforms the multi-shift variant by a factor of two.