Parallelizing the QUDA Library for Multi-GPU Calculations in Lattice Quantum Chromodynamics

Babich, Ronald; Clark, Michael A.; Joó, Bálint

doi:10.1109/sc.2010.40

Cited by 88 publications

(85 citation statements)

References 26 publications

(44 reference statements)

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“…The software codes Chroma [58] and QUDA [59,60] were used to perform this work at Jefferson Laboratory under the USQCD Initiative and the LQCD ARRA project, and on the Lonsdale cluster maintained by the Trinity Centre for High Performance Computing funded through grants from Science Foundation Ireland (SFI). This work also used the DiRAC Data Analytic system at the University of Cambridge, operated by the University of Cambridge High Performance Computing Service on behalf of the STFC DiRAC HPC Facility (www.dirac.ac.uk).…”

Section: Discussionmentioning

confidence: 99%

Coupled-channel Dπ, Dη and D s K ¯ $$ {D}_s\overline{K} $$ scattering from lattice QCD

Moir

Peardon

Ryan

et al. 2016

J. High Energ. Phys.

172

266

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We present the first lattice QCD study of coupled-channel Dπ, Dη and D sK scattering in isospin-1/2 in three partial waves. Using distillation, we compute matrices of correlation functions with bases of operators capable of resolving both meson and mesonmeson contributions to the spectrum. These correlation matrices are analysed using a variational approach to extract the finite-volume energy eigenstates. Utilising Lüscher's method and its extensions, we constrain scattering amplitudes in S, P and D-wave as a function of energy. By analytically continuing the scattering amplitudes to complex energies, we investigate the S-matrix singularities. Working at m π ≈ 391 MeV, we find a pole corresponding to a J P = 0 + near-threshold bound state with a large coupling to Dπ. We also find a deeply bound J P = 1 − state, and evidence for a J P = 2 + narrow resonance coupled predominantly to Dπ. Elastic Dπ scattering in the isospin-3/2 channel is studied and we find a weakly repulsive interaction in S-wave.

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Section: Discussionmentioning

confidence: 99%

Coupled-channel Dπ, Dη and D s K ¯ $$ {D}_s\overline{K} $$ scattering from lattice QCD

Moir

Peardon

Ryan

et al. 2016

J. High Energ. Phys.

172

266

View full text Add to dashboard Cite

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“…Systems may be considered having non-zero overall momentum, P = 2π L n x , n y , n z , which satisfy periodic boundary conditions if n x , n y , n z are integers. Such 1 The large number of propagators are very efficiently computed using an Adaptive Multi-Grid solver [32,33] for the light quarks on CPUs, and the strange quark propagators are efficiently computed using Graphical Processing Units [34,35]. Table I.…”

Section: Calculating the Finite-volume Spectrummentioning

confidence: 99%

Coupledππ,KK¯scattering inP

et al. 2015

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We determine elastic and coupled-channel amplitudes for isospin-1 meson-meson scattering in P -wave, by calculating correlation functions using lattice QCD with light quark masses such that mπ = 236 MeV in a cubic volume of ∼ (4 fm)3 . Variational analyses of large matrices of correlation functions computed using operator constructions resembling ππ, KK and qq, in several moving frames and several lattice irreducible representations, leads to discrete energy spectra from which scattering amplitudes are extracted. In the elastic ππ scattering region we obtain a detailed energydependence for the phase-shift, corresponding to a ρ resonance, and we extend the analysis into the coupled-channel KK region for the first time, finding a small coupling between the channels.The study of hadron spectroscopy from first principles QCD is entering a new stage of development where the relationship between the discrete spectrum of the theory in a finite-volume and the infinite-volume scattering amplitudes is being practically utilized to study resonances. The tool which allows us access to the spectrum is lattice QCD in which the quark and gluon fields are considered on a finite-grid of points with only systematically improvable approximations being made.Predictably it is the simplest resonant scattering channel which has attracted the greatest initial interest [1][2][3][4][5], that of ππ with isospin=1, in which a low-lying elastic vector resonance called the ρ appears. These works have made use of the formalism relating the discrete spectrum at rest and in moving frames to elastic scattering amplitudes, which has been in place for many years [6][7][8][9][10]. Recently the extension to coupled-channels has been presented [11][12][13][14], and the first lattice QCD study of a coupled-channel system, that of πK, ηK in S, P and Dwaves, has appeared [15,16], showing that the energy dependence and resonant content of the scattering matrix for such a system can be extracted from finite volume spectra.To date virtually all determinations of hadron scattering amplitudes in lattice QCD calculations have worked with artificially heavy u, d quark mass values, a choice which leads to heavier than physical pseudoscalar mesons -this reduces the computational cost, allowing calculations in smaller volumes (where m π L remains large), and pushes up in energy the thresholds for multihadron scattering such as ππππ, for which a finite-volume formalism is not yet in place (but see Refs. [17][18][19][20] The Hadron Spectrum Collaboration previously computed ππ scattering using 391 MeV pions [21,22], extracting detailed spectra of QCD eigenstates from variational analysis of two-point correlation functions computed in several moving frames in three different volumes. By obtaining a significant number of energy levels in the elastic scattering region they were able to map out the energy dependence of the scattering amplitude and show that there is a narrow ρ resonance barely above ππ threshold.In this paper we deliver an extension of the work presen...

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“…Support for GPUs is based on the QUDA library [3], originally developed at Boston University (BU). The extension to staggered quarks began when one of us was on sabbatical at the National Center for Supercomputing Applications (NCSA) at the University of Illinois.…”

Section: Development Of the Milc Codementioning

confidence: 99%

MILC Code Performance on High End CPU and GPU Supercomputer Clusters

DeTar

Gottlieb

et al. 2018

EPJ Web Conf.

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Abstract. With recent developments in parallel supercomputing architecture, many core, multi-core, and GPU processors are now commonplace, resulting in more levels of parallelism, memory hierarchy, and programming complexity. It has been necessary to adapt the MILC code to these new processors starting with NVIDIA GPUs, and more recently, the Intel Xeon Phi processors. We report on our efforts to port and optimize our code for the Intel Knights Landing architecture. We consider performance of the MILC code with MPI and OpenMP, and optimizations with QOPQDP and QPhiX. For the latter approach, we concentrate on the staggered conjugate gradient and gauge force. We also consider performance on recent NVIDIA GPUs using the QUDA library.

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Parallelizing the QUDA Library for Multi-GPU Calculations in Lattice Quantum Chromodynamics

Cited by 88 publications

References 26 publications

Coupled-channel Dπ, Dη and D s K ¯ $$ {D}_s\overline{K} $$ scattering from lattice QCD

Coupled-channel Dπ, Dη and D s K ¯ $$ {D}_s\overline{K} $$ scattering from lattice QCD

Coupledππ,KK¯scattering inP

MILC Code Performance on High End CPU and GPU Supercomputer Clusters

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