high performance computing on graphics processing units: hgpu.org

We have developed the astrophysical simulation code XFLAT to study neutrino oscillations in supernovae. XFLAT is designed to utilize multiple levels of parallelism through MPI, OpenMP, and SIMD instructions (vectorization). It can run on both CPU and Xeon Phi co-processors based on the Intel Many Integrated Core Architecture (MIC). We analyze the performance of XFLAT […]

Multi-GPU implementations of the Lattice Boltzmann method are of practical interest as they allow the study of turbulent flows on large-scale simulations at high Reynolds numbers. Although programming GPUs, and in general power-efficient accelerators, typically guarantees high performances, the lack of portability in their low-level programming models implies significant efforts for maintainability and porting of […]

In this work we study the implementations of deflation and preconditioning techniques for solving ill-conditioned linear systems using iterative methods. Solving such systems can be a time-consuming process because of the jumps in the coefficients due to large difference in material properties. We have developed implementations of the iterative methods with these preconditioning techniques on […]

In this article, we introduce CURRENNT, an open-source parallel implementation of deep recurrent neural networks (RNNs) supporting graphics processing units (GPUs) through NVIDIA’s Computed Unified Device Architecture (CUDA). CURRENNT supports uni- and bidirectional RNNs with Long Short-Term Memory (LSTM) memory cells which overcome the vanishing gradient problem. To our knowledge, CURRENNT is the first publicly […]

The 2D Least Median of Squares (LMS) is a popular tool in robust regression because of its high breakdown point: up to half of the input data can be contaminated with outliers without affecting the accuracy of the LMS estimator. The complexity of 2D LMS estimation has been shown to be $Omega(n^2)$ where $n$ is […]

With large-scale Integral Field Spectroscopy (IFS) surveys of thousands of galaxies currently under-way or planned, the astronomical community is in need of methods, techniques and tools that will allow the analysis of huge amounts of data. We focus on the kinematic modelling of disc galaxies and investigate the potential use of massively parallel architectures, such […]

The Quadratic Assignment Problem, QAP, is a classic combinatorial optimization problem, classified as NP-hard and widely studied. This problem consists in assigning N facilities to N locations obeying the relation of 1 to 1, aiming to minimize costs of the displacement between the facilities. The application of Reformulation and Linearization Technique, RLT, to the QAP […]

OmpSs is a task-parallel programming model consisting of a reduced collection of OpenMP-like directives, a front-end compiler, and a runtime system. This directive-based programming interface helps developers accelerate their application’s execution, e.g. in a cluster equipped with graphics processing units (GPUs), with a low programming effort. On the other hand, the virtualization package rCUDA provides […]

Complex networks have received interest in a wide area of applications, ranging from road networks over hyperlink connections in the world wide web to interactions between people. Advanced algorithms are required for the generation as well as visualization of such graphs. In this work two graph algorithms, one for graph generation, the other for graph […]

The massive parallelism and faster random memory access of Graphics Processing Units (GPUs) promise to further accelerate complex analytics operations such as joins and grouping, but also provide additional challenges to optimizing their performance. There are more implementation alternatives to consider on the GPU, such as exploiting different types of memory on the device and […]

Array-based languages such as MATLAB and Python (with NumPy) have become very popular for scientific computing. However, the performance of the implementations of these languages is often lacking. For example, some of the implementations are interpreted. Further, these languages were not designed with multi-core CPUs and GPUs in mind and thus don’t take full advantage […]

Nowadays, real-time video communication over the internet through video conferencing applications has become an invaluable tool in everyone’s professional and personal life. This trend underlines the need for video coding algorithms that provide acceptable quality on low bitrates and can support various resolutions inside the same stream in order to cope with limitations on computational […]