Ocelot 2.0.969 brings CUDA 3.2 and Fermi support to a stable release. Ocelot is a BSD-licensed open source implementation of the CUDA runtime, a PTX emulator, and a mid-level PTX compiler.
Here is a feature list for 2.0.969:
- PTX 2.2 and Fermi device support: Floating point results should be within the ULP limits in the PTX ISA manual. Over 500 unit tests verify that the behaviour matches NVIDIA devices.
- Four target device types: A functional PTX emulator. A PTX to LLVM to x86/ARM JIT. A PTX to CAL JIT for AMD devices (beta). A PTX to PTX JIT for NVIDIA devices.
- A full-featured PTX 2.2 IR: An analysis/optimization pass interface over PTX (Control flow graph, dataflow graph, dominator/postdominator trees, structured control tree). Optimizations can be plugged in as modules.
- Correctness checking tools: A memory checker (detects unaligned and out of bounds accesses). A race detector. An interactive debugger (allows stepping through PTX instructions).
- An instruction trace analyzer interface: Allows user-defined modules to receive callbacks when PTX instructions are executed. Can be used to compute metrics over applications or perform correctness checks.
- A CUDA API frontend: Existing CUDA programs can be directly linked against Ocelot. Device pointers can be shared across host threads. Multiple devices can be controlled from the same host thread (cudaSetDevice can be called multiple times).
Ocelot is available under a BSD license at http://code.google.com/p/gpuocelot.
Submissions are cordially invited for the Workshop on GPU Computing, held with PPAM 2011 — 9th International Conference on Parallel Processing and Applied Mathematics, September 11-14, 2011, Torun, Poland. This workshop is organised by Josep R. Herrero, Enrique S. Quintana-Orti, and Robert Strzodka.
GPU programming is now a much richer environment that it used to be a few years ago. On top of the two major programming languages, CUDA and OpenCL, libraries (e.g., cufft) and high level interfaces (e.g., thrust) have been developed that allow a fast access to the computing power of GPUs without detailed knowledge or programming of GPU hardware.
Annotation-based programming models (e.g., PGI Accelerator), GPU plug-ins for existing mathematical software (e.g., Jacket in Matlab), GPU script languages (e.g., PyOpenCL), and new data parallel languages (e.g., Copperhead) bring GPU programming to a new level. Read the rest of this entry »
We examine the problem of segmenting foreground objects in live video when background scene textures change over time. In particular, we formulate background subtraction as minimizing a penalized instantaneous risk functional yielding a local on-line discriminative algorithm that can quickly adapt to temporal changes. We analyze the algorithms convergence, discuss its robustness to non-stationarity, and provide an efficient non-linear extension via sparse kernels. To accommodate interactions among neighboring pixels, a global algorithm is then derived that explicitly distinguishes objects versus background using maximum a posteriori inference in a Markov random field (implemented via graph-cuts). By exploiting the parallel nature of the proposed algorithms, we develop an implementation that can run efficiently on the highly parallel Graphics Processing Unit (GPU). Empirical studies on a wide variety of datasets demonstrate that the proposed approach achieves quality that is comparable to state-of-the-art off-line methods, while still being suitable for real-time video analysis (75 fps on a mid-range GPU).
(Li Cheng, M. Gong, D. Schuurmans, and T. Caelli: “Real-time Discriminative Background Subtraction”. IEEE Transactions on Image Processing, 2011, to appear. [DOI] [Sources & Info])
The Pan-American Advanced Studies Institute (PASI)—”Scientific Computing in the Americas: the challenge of massive parallelism”—was held in Valparaiso, Chile on 3–14 January 2011. The event hosted 14 lecturers and 68 participants, thanks to NSF/DOE funding. Lecture materials are now available publicly: PDFs of the lecture slides on the PASI website, and screencasts (video) via an iTunes U course and on YouTube also).
Exploitation of novel computer architectures, such as general purpose GPUs, is allowing researchers to accelerate the realization of frontier models in particle-based simulation, by enabling an increase in the level of realism in the description of the particles and their interactions and increasing both the number of particles and the timescales simulated.
This one-day meeting focuses on the new and exciting area of the exploitation of GPUs and related technology in the area of biomolecular simulations.
In addition to a programme of national and international speakers in the field, there is the opportunity to present a poster on your research. Read the rest of this entry »
The Parallel Processing for Imaging Applications conference, part of IS&T/SPIE’s Electronic Imaging conference, was held on January 24–25 in San Francisco. The conference had a large number of GPU papers (SPIE digital library link):
SpeedIT Extreme 1.2 introduces support for complex numbers in single and double precision for all SpeedIT methods, such as fast sparse matrix vector multiplication, CG and BiCGSTAB solver.
This new report covers all the performance improvements in the latest CUDA Toolkit 3.2 release, and compares CUDA parallel math library performance vs. commonly used CPU libraries.
Learn about the performance advantages of using the CUDA parallel math libraries for FFT, BLAS, sparse matrix operations, and random number generation.
We implemented a GPU based parallel code to perform Monte Carlo simulations of the two dimensional q-state Potts model. The algorithm is based on a checkerboard update scheme and assigns independent random number generators to each thread (one thread per spin). The implementation allows to simulate systems up to ~10^9 spins with an average time per spin flip of 0.147ns on the fastest GPU card tested, representing a speedup up to 155x, compared with an optimized serial code running on a standard CPU. The possibility of performing high speed simulations at large enough system sizes allowed us to provide a positive numerical evidence about the existence of metastability on very large systems based on Binder’s criterion, namely, on the existence or not of specific heat singularities at spinodal temperatures different of the transition one.
(Ezequiel E. Ferrero, Juan Pablo De Francesco, Nicolás Wolovick and Sergio A. Cannas: “q-state Potts model metastability study using optimized GPU-based Monte Carlo algorithms”. [arXiv:1101.0876] [code and additional information])
This meeting is organized by Toby Breckon & Stuart Barnes (Cranfield University) and the British Machine Vision Association and Society for Pattern Recognition. It will be held in London, UK, on 18 May 2011. The CfP poster is available at http://www.cranfield.ac.uk/~toby.breckon/events/bmva_symp_gpu11.pdf.
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