5,890 research outputs found
A GPU-enabled implicit Finite Volume solver for the ideal two-fluid plasma model on unstructured grids
This paper describes the main features of a pioneering unsteady solver for
simulating ideal two-fluid plasmas on unstructured grids, taking profit of
GPGPU (General-purpose computing on graphics processing units). The code, which
has been implemented within the open source COOLFluiD platform, is implicit,
second-order in time and space, relying upon a Finite Volume method for the
spatial discretization and a three-point backward Euler for the time
integration. In particular, the convective fluxes are computed by a multi-fluid
version of the AUSM+up scheme for the plasma equations, in combination with a
modified Rusanov scheme with tunable dissipation for the Maxwell equations.
Source terms are integrated with a one-point rule, using the cell-centered
value. Some critical aspects of the porting to GPU's are discussed, as well as
the performance of two open source linear system solvers (i.e. PETSc,
PARALUTION). The code design allows for computing both flux and source terms on
the GPU along with their Jacobian, giving a noticeable decrease in the
computational time in comparison with the original CPU-based solver. The code
has been tested in a wide range of mesh sizes and in three different systems,
each one with a different GPU. The increased performance (up to 14x) is
demonstrated in two representative 2D benchmarks: propagation of circularly
polarized waves and the more challenging Geospace Environmental Modeling (GEM)
magnetic reconnection challenge.Comment: 22 pages, 7 figure
QCD simulations with staggered fermions on GPUs
We report on our implementation of the RHMC algorithm for the simulation of
lattice QCD with two staggered flavors on Graphics Processing Units, using the
NVIDIA CUDA programming language. The main feature of our code is that the GPU
is not used just as an accelerator, but instead the whole Molecular Dynamics
trajectory is performed on it. After pointing out the main bottlenecks and how
to circumvent them, we discuss the obtained performances. We present some
preliminary results regarding OpenCL and multiGPU extensions of our code and
discuss future perspectives.Comment: 22 pages, 14 eps figures, final version to be published in Computer
Physics Communication
Comparison of the Structure of Equation Systems and the GPU Multifrontal Solver for Finite Difference, Collocation and Finite Element Method
AbstractThe article is an in-depth comparison of numerical solvers and corresponding solution pro- cesses of the systems of algebraic equations resulting from finite difference, collocation, and finite element approximations. The paper considers recently developed isogeometric versions of the collocation and finite element methods, employing B-splines for the computations and ensuring Cpâ1 continuity on the borders of elements for the B-splines of the order p. For solving the systems, we use our GPU implementation of the state-of-the-art parallel multifrontal solver, which leverages modern GPU architectures and allows to reduce the complexity. We analyze the structures of linear equation systems resulting from each of the methods and how different matrix structures lead to different multifrontal solver elimination trees. The paper also considers the flows of multifrontal solver depending on the originally employed method
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