Graphics Processing Units (GPUs) can speed up the numerical solution of various problems in astrophysics including the dynamical evolution of stellar systems; the performance gain can be more than a factor 100 compared to using a Central Processing Unit only. In this work I describe some strategies to speed up the classical N-body problem using […]

November 20, 2014 by hgpu

Modeling large-scale sky survey observations is a key driver for the continuing development of high resolution, large-volume, cosmological simulations. We report the first results from the ‘Q Continuum’ cosmological N-body simulation run carried out on the GPU-accelerated supercomputer Titan. The simulation encompasses a volume of (1300 Mpc)^3 and evolves more than half a trillion particles, […]

November 16, 2014 by hgpu

An observation in supercomputing in the past decade illustrates the transition of pervasive commodity products being integrated with the world’s fastest system. Given today’s exploding popularity of mobile devices, we investigate the possibilities for high performance mobile computing. Because parallel processing on mobile devices will be the key element in developing a mobile and computationally […]

October 14, 2014 by hgpu

Current and future surveys of large-scale cosmic structure are associated with a massive and complex datastream to study, characterize, and ultimately understand the physics behind the two major components of the ‘Dark Universe’, dark energy and dark matter. In addition, the surveys also probe primordial perturbations and carry out fundamental measurements, such as determining the […]

October 13, 2014 by hgpu

We review the recent optimizations of gravitational N-body kernels for running them on graphics processing units (GPUs), on single hosts and massive parallel platforms. For each of the two main N-body techniques, direct summation and tree-codes, we discuss the optimization strategy, which is different for each algorithm. Because both the accuracy as well as the […]

September 23, 2014 by hgpu

Molecular dynamics simulations allow us to study the behavior of complex biomolecular systems by modeling the pairwise interaction forces between all atoms. Molecular systems are subject to slowly decaying electrostatic potentials, which turn molecular dynamics into an n-body problem. In this paper, we present a parallel and scalable solution to compute long-range molecular forces, based […]

September 15, 2014 by hgpu

The Dark Sky Simulations are an ongoing series of cosmological N-body simulations designed to provide a quantitative and accessible model of the evolution of the large-scale Universe. Such models are essential for many aspects of the study of dark matter and dark energy, since we lack a sufficiently accurate analytic model of non-linear gravitational clustering. […]

July 22, 2014 by hgpu

N-body simulations represent an important class of numerical simulations in order to study a wide range of physical phenomena for which researchers demand fast and accurate implementations. Due to the computational complexity, simple brute-force methods to solve the long-distance interaction between bodies can only be used for small-scale simulations. Smarter approaches utilize neighbor lists, tree […]

July 1, 2014 by hgpu

Cosmological simulations are used by astronomers to investigate large scale structure formation and galaxy evolution. Structure finding, that is, the discovery of gravitationally-bound objects such as dark matter halos, is a crucial step in many such simulations. During recent years, advancing computational capacity has lead to halo-finders needing to manage increasingly larger simulations. As a […]

July 1, 2014 by hgpu

The simulation of a fiber suspension requires that all interactions between the fibers involved are computed. This is a compute-intensive N-body problem that is highly data parallel. Using the GPU for these types of computations can be very beneficial. In this thesis an extension to a simulator, written in MATLAB, for rigid fibers in Stokes […]

June 25, 2014 by hgpu

We propose a hybrid tree algorithm for reducing calculation and communication cost of collision-less N-body simulations. The concept of our algorithm is that we split interaction force into two parts: hard-force from neighbor particles and soft-force from distant particles, and applying different time integration for the forces. For hard-force calculation, we can efficiently reduce the […]

June 25, 2014 by hgpu

Exascale systems are predicted to have approximately one billion cores, assuming Gigahertz cores. Limitations on affordable network topologies for distributed memory systems of such massive scale bring new challenges to the current parallel programing model. Currently, there are many efforts to evaluate the hardware and software bottlenecks of exascale designs. There is therefore an urgent […]

June 1, 2014 by hgpu