17,305 research outputs found
Porting a parallel program from the NASA Center for Climate Simulation (NCCS) Discoverer supercomputer to desktops for validation of the Multi-sensor Aerosol Products Sampling System (MAPSS)
The National Aeronautics and Space Administration (NASA) produces nearly two gigabytes of data per second. NASA researchers leverage millions of dollars of computing hardware to analyze this data. NASA shares this data with the rest of the world. Advances in computer technology have provided modern desktop computers more powerful than the fastest supercomputers in the world from two and three decades ago. This provides many possibilities for greater use of NASA data. A lack of education materials for undergraduate research in high performance computing limits these possibilities. This research addresses this need by presenting the methodologies used to translate the NASA MAPSS software system from supercomputers and software engineers to desktops and undergrads. Undergraduate student researchers studied the MAPSS software system, created for the NASA Goddard Space Flight Center supercomputers, to conduct a validation study of NASA Earth Atmosphere aerosol data. Undergrads rewrote parts of the software allowing it to run on an Intel \1 processor running a Linux system. The students completed translation of four of the seven satellite sensors, and developed automation software allowing MAPSS to be portable between individual computers. The students provided documentation of this process allowing future students to complete the translation of the remaining sensor systems and the validation study. This should provide greater use of the data that streams from NASA every day
Warp-X: a new exascale computing platform for beam-plasma simulations
Turning the current experimental plasma accelerator state-of-the-art from a
promising technology into mainstream scientific tools depends critically on
high-performance, high-fidelity modeling of complex processes that develop over
a wide range of space and time scales. As part of the U.S. Department of
Energy's Exascale Computing Project, a team from Lawrence Berkeley National
Laboratory, in collaboration with teams from SLAC National Accelerator
Laboratory and Lawrence Livermore National Laboratory, is developing a new
plasma accelerator simulation tool that will harness the power of future
exascale supercomputers for high-performance modeling of plasma accelerators.
We present the various components of the codes such as the new Particle-In-Cell
Scalable Application Resource (PICSAR) and the redesigned adaptive mesh
refinement library AMReX, which are combined with redesigned elements of the
Warp code, in the new WarpX software. The code structure, status, early
examples of applications and plans are discussed
Tackling Exascale Software Challenges in Molecular Dynamics Simulations with GROMACS
GROMACS is a widely used package for biomolecular simulation, and over the
last two decades it has evolved from small-scale efficiency to advanced
heterogeneous acceleration and multi-level parallelism targeting some of the
largest supercomputers in the world. Here, we describe some of the ways we have
been able to realize this through the use of parallelization on all levels,
combined with a constant focus on absolute performance. Release 4.6 of GROMACS
uses SIMD acceleration on a wide range of architectures, GPU offloading
acceleration, and both OpenMP and MPI parallelism within and between nodes,
respectively. The recent work on acceleration made it necessary to revisit the
fundamental algorithms of molecular simulation, including the concept of
neighborsearching, and we discuss the present and future challenges we see for
exascale simulation - in particular a very fine-grained task parallelism. We
also discuss the software management, code peer review and continuous
integration testing required for a project of this complexity.Comment: EASC 2014 conference proceedin
GHOST: Building blocks for high performance sparse linear algebra on heterogeneous systems
While many of the architectural details of future exascale-class high
performance computer systems are still a matter of intense research, there
appears to be a general consensus that they will be strongly heterogeneous,
featuring "standard" as well as "accelerated" resources. Today, such resources
are available as multicore processors, graphics processing units (GPUs), and
other accelerators such as the Intel Xeon Phi. Any software infrastructure that
claims usefulness for such environments must be able to meet their inherent
challenges: massive multi-level parallelism, topology, asynchronicity, and
abstraction. The "General, Hybrid, and Optimized Sparse Toolkit" (GHOST) is a
collection of building blocks that targets algorithms dealing with sparse
matrix representations on current and future large-scale systems. It implements
the "MPI+X" paradigm, has a pure C interface, and provides hybrid-parallel
numerical kernels, intelligent resource management, and truly heterogeneous
parallelism for multicore CPUs, Nvidia GPUs, and the Intel Xeon Phi. We
describe the details of its design with respect to the challenges posed by
modern heterogeneous supercomputers and recent algorithmic developments.
Implementation details which are indispensable for achieving high efficiency
are pointed out and their necessity is justified by performance measurements or
predictions based on performance models. The library code and several
applications are available as open source. We also provide instructions on how
to make use of GHOST in existing software packages, together with a case study
which demonstrates the applicability and performance of GHOST as a component
within a larger software stack.Comment: 32 pages, 11 figure
MPWide: a light-weight library for efficient message passing over wide area networks
We present MPWide, a light weight communication library which allows
efficient message passing over a distributed network. MPWide has been designed
to connect application running on distributed (super)computing resources, and
to maximize the communication performance on wide area networks for those
without administrative privileges. It can be used to provide message-passing
between application, move files, and make very fast connections in
client-server environments. MPWide has already been applied to enable
distributed cosmological simulations across up to four supercomputers on two
continents, and to couple two different bloodflow simulations to form a
multiscale simulation.Comment: accepted by the Journal Of Open Research Software, 13 pages, 4
figures, 1 tabl
Компьютерное моделирование в атомной энергетике
Report is devoted to computer technologies for nuclear power, namely need of their rapid development for Russia. The special attention is paid to results operating projects and to the forecast for some future plans of development of these technologies. Their ability to solve many actual problems of nuclear power is shown. Also report gives justification of economic benefits of these technologies: decrease the number of natural experiments and, as a consequence, the resources spent. Adequacy of use is confirmed by some examples of numerical model operation with some domestically produced software packages for supercomputers
A review of High Performance Computing foundations for scientists
The increase of existing computational capabilities has made simulation
emerge as a third discipline of Science, lying midway between experimental and
purely theoretical branches [1, 2]. Simulation enables the evaluation of
quantities which otherwise would not be accessible, helps to improve
experiments and provides new insights on systems which are analysed [3-6].
Knowing the fundamentals of computation can be very useful for scientists, for
it can help them to improve the performance of their theoretical models and
simulations. This review includes some technical essentials that can be useful
to this end, and it is devised as a complement for researchers whose education
is focused on scientific issues and not on technological respects. In this
document we attempt to discuss the fundamentals of High Performance Computing
(HPC) [7] in a way which is easy to understand without much previous
background. We sketch the way standard computers and supercomputers work, as
well as discuss distributed computing and discuss essential aspects to take
into account when running scientific calculations in computers.Comment: 33 page
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