863 research outputs found
Status and Future Perspectives for Lattice Gauge Theory Calculations to the Exascale and Beyond
In this and a set of companion whitepapers, the USQCD Collaboration lays out
a program of science and computing for lattice gauge theory. These whitepapers
describe how calculation using lattice QCD (and other gauge theories) can aid
the interpretation of ongoing and upcoming experiments in particle and nuclear
physics, as well as inspire new ones.Comment: 44 pages. 1 of USQCD whitepapers
Solving Lattice QCD systems of equations using mixed precision solvers on GPUs
Modern graphics hardware is designed for highly parallel numerical tasks and
promises significant cost and performance benefits for many scientific
applications. One such application is lattice quantum chromodyamics (lattice
QCD), where the main computational challenge is to efficiently solve the
discretized Dirac equation in the presence of an SU(3) gauge field. Using
NVIDIA's CUDA platform we have implemented a Wilson-Dirac sparse matrix-vector
product that performs at up to 40 Gflops, 135 Gflops and 212 Gflops for double,
single and half precision respectively on NVIDIA's GeForce GTX 280 GPU. We have
developed a new mixed precision approach for Krylov solvers using reliable
updates which allows for full double precision accuracy while using only single
or half precision arithmetic for the bulk of the computation. The resulting
BiCGstab and CG solvers run in excess of 100 Gflops and, in terms of iterations
until convergence, perform better than the usual defect-correction approach for
mixed precision.Comment: 30 pages, 7 figure
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