Publications

Results 201–313 of 313
Skip to search filters

Demonstration of a Legacy Application's Path to Exascale - ASC L2 Milestone 4467

Barrett, Brian B.; Kelly, Suzanne M.; Klundt, Ruth A.; Laros, James H.; Leung, Vitus J.; Levenhagen, Michael J.; Lofstead, Gerald F.; Moreland, Kenneth D.; Oldfield, Ron A.; Pedretti, Kevin P.; Rodrigues, Arun; Barrett, Richard F.; Ward, Harry L.; Vandyke, John P.; Vaughan, Courtenay T.; Wheeler, Kyle B.; Brandt, James M.; Brightwell, Ronald B.; Curry, Matthew L.; Fabian, Nathan D.; Ferreira, Kurt; Gentile, Ann C.; Hemmert, Karl S.

Abstract not provided.

More Details
TYPE Presentation YEAR 2012
OSTI

Report of experiments and evidence for ASC L2 milestone 4467 : demonstration of a legacy application's path to exascale

Barrett, Brian B.; Kelly, Suzanne M.; Klundt, Ruth A.; Laros, James H.; Leung, Vitus J.; Levenhagen, Michael J.; Lofstead, Gerald F.; Moreland, Kenneth D.; Oldfield, Ron A.; Pedretti, Kevin P.; Rodrigues, Arun; Barrett, Richard F.; Ward, Harry L.; Vandyke, John P.; Vaughan, Courtenay T.; Wheeler, Kyle B.; Brandt, James M.; Brightwell, Ronald B.; Curry, Matthew L.; Fabian, Nathan D.; Ferreira, Kurt; Gentile, Ann C.; Hemmert, Karl S.

This report documents thirteen of Sandia's contributions to the Computational Systems and Software Environment (CSSE) within the Advanced Simulation and Computing (ASC) program between fiscal years 2009 and 2012. It describes their impact on ASC applications. Most contributions are implemented in lower software levels allowing for application improvement without source code changes. Improvements are identified in such areas as reduced run time, characterizing power usage, and Input/Output (I/O). Other experiments are more forward looking, demonstrating potential bottlenecks using mini-application versions of the legacy codes and simulating their network activity on Exascale-class hardware. The purpose of this report is to prove that the team has completed milestone 4467-Demonstration of a Legacy Application's Path to Exascale. Cielo is expected to be the last capability system on which existing ASC codes can run without significant modifications. This assertion will be tested to determine where the breaking point is for an existing highly scalable application. The goal is to stretch the performance boundaries of the application by applying recent CSSE RD in areas such as resilience, power, I/O, visualization services, SMARTMAP, lightweight LWKs, virtualization, simulation, and feedback loops. Dedicated system time reservations and/or CCC allocations will be used to quantify the impact of system-level changes to extend the life and performance of the ASC code base. Finally, a simulation of anticipated exascale-class hardware will be performed using SST to supplement the calculations. Determine where the breaking point is for an existing highly scalable application: Chapter 15 presented the CSSE work that sought to identify the breaking point in two ASC legacy applications-Charon and CTH. Their mini-app versions were also employed to complete the task. There is no single breaking point as more than one issue was found with the two codes. The results were that applications can expect to encounter performance issues related to the computing environment, system software, and algorithms. Careful profiling of runtime performance will be needed to identify the source of an issue, in strong combination with knowledge of system software and application source code.

More Details
TYPE SAND Report YEAR 2012
OSTIDOI

Dax toolkit: A proposed framework for data analysis and visualization at extreme scale

1st IEEE Symposium on Large-Scale Data Analysis and Visualization 2011, LDAV 2011 - Proceedings

Moreland, Kenneth D.; Ayachit, Utkarsh; Geveci, Berk; Ma, Kwan L.

Experts agree that the exascale machine will comprise processors that contain many cores, which in turn will necessitate a much higher degree of concurrency. Software will require a minimum of a 1,000 times more concurrency. Most parallel analysis and visualization algorithms today work by partitioning data and running mostly serial algorithms concurrently on each data partition. Although this approach lends itself well to the concurrency of current high-performance computing, it does not exhibit the appropriate pervasive parallelism required for exascale computing. The data partitions are too small and the overhead of the threads is too large to make effective use of all the cores in an extreme-scale machine. This paper introduces a new visualization framework designed to exhibit the pervasive parallelism necessary for extreme scale machines. We demonstrate the use of this system on a GPU processor, which we feel is the best analog to an exascale node that we have available today. © 2011 IEEE.

More Details
TYPE Conference YEAR 2011
ScopusOSTI

IceT users' guide and reference

Moreland, Kenneth D.

The Image Composition Engine for Tiles (IceT) is a high-performance sort-last parallel rendering library. In addition to providing accelerated rendering for a standard display, IceT provides the unique ability to generate images for tiled displays. The overall resolution of the display may be several times larger than any viewport that may be rendered by a single machine. This document is an overview of the user interface to IceT.

More Details
TYPE SAND Report YEAR 2011
OSTIDOI

Visualization on supercomputing platform level II ASC milestone (3537-1B) results from Sandia

Moreland, Kenneth D.; Fabian, Nathan D.

This report provides documentation for the completion of the Sandia portion of the ASC Level II Visualization on the platform milestone. This ASC Level II milestone is a joint milestone between Sandia National Laboratories and Los Alamos National Laboratories. This milestone contains functionality required for performing visualization directly on a supercomputing platform, which is necessary for peta-scale visualization. Sandia's contribution concerns in-situ visualization, running a visualization in tandem with a solver. Visualization and analysis of petascale data is limited by several factors which must be addressed as ACES delivers the Cielo platform. Two primary difficulties are: (1) Performance of interactive rendering, which is most computationally intensive portion of the visualization process. For terascale platforms, commodity clusters with graphics processors(GPUs) have been used for interactive rendering. For petascale platforms, visualization and rendering may be able to run efficiently on the supercomputer platform itself. (2) I/O bandwidth, which limits how much information can be written to disk. If we simply analyze the sparse information that is saved to disk we miss the opportunity to analyze the rich information produced every timestep by the simulation. For the first issue, we are pursuing in-situ analysis, in which simulations are coupled directly with analysis libraries at runtime. This milestone will evaluate the visualization and rendering performance of current and next generation supercomputers in contrast to GPU-based visualization clusters, and evaluate the performance of common analysis libraries coupled with the simulation that analyze and write data to disk during a running simulation. This milestone will explore, evaluate and advance the maturity level of these technologies and their applicability to problems of interest to the ASC program. Scientific simulation on parallel supercomputers is traditionally performed in four sequential steps: meshing, partitioning, solver, and visualization. Not all of these components are necessarily run on the supercomputer. In particular, the meshing and visualization typically happen on smaller but more interactive computing resources. However, the previous decade has seen a growth in both the need and ability to perform scalable parallel analysis, and this gives motivation for coupling the solver and visualization.

More Details
TYPE SAND Report YEAR 2010
OSTIDOI

Diverging color maps for scientific visualization

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Moreland, Kenneth D.

One of the most fundamental features of scientific visualization is the process of mapping scalar values to colors. This process allows us to view scalar fields by coloring surfaces and volumes. Unfortunately, the majority of scientific visualization tools still use a color map that is famous for its ineffectiveness: the rainbow color map. This color map, which naïvely sweeps through the most saturated colors, is well known for its ability to obscure data, introduce artifacts, and confuse users. Although many alternate color maps have been proposed, none have achieved widespread adoption by the visualization community for scientific visualization. This paper explores the use of diverging color maps (sometimes also called ratio, bipolar, or double-ended color maps) for use in scientific visualization, provides a diverging color map that generally performs well in scientific visualization applications, and presents an algorithm that allows users to easily generate their own customized color maps. © 2009 Springer-Verlag.

More Details
TYPE Conference YEAR 2009
ScopusOSTI

Scalable analysis tools for sensitivity analysis and UQ (3160) results

Ice, Lisa I.; Fabian, Nathan D.; Moreland, Kenneth D.; Bennett, Janine C.; Karelitz, David B.

The 9/30/2009 ASC Level 2 Scalable Analysis Tools for Sensitivity Analysis and UQ (Milestone 3160) contains feature recognition capability required by the user community for certain verification and validation tasks focused around sensitivity analysis and uncertainty quantification (UQ). These feature recognition capabilities include crater detection, characterization, and analysis from CTH simulation data; the ability to call fragment and crater identification code from within a CTH simulation; and the ability to output fragments in a geometric format that includes data values over the fragments. The feature recognition capabilities were tested extensively on sample and actual simulations. In addition, a number of stretch criteria were met including the ability to visualize CTH tracer particles and the ability to visualize output from within an S3D simulation.

More Details
TYPE SAND Report YEAR 2009
OSTIDOI

IceT users' guide and reference

Moreland, Kenneth D.

The Image Composition Engine for Tiles (IceT) is a high-performance sort-last parallel rendering library. In addition to providing accelerated rendering for a standard display, IceT provides the unique ability to generate images for tiled displays. The overall resolution of the display may be several times larger than any viewport that may be rendered by a single machine. This document is an overview of the user interface to IceT.

More Details
TYPE SAND Report YEAR 2009
OSTIDOI

Post-processing V&V Level II ASC Milestone (2843) results

Moreland, Kenneth D.; Wilke, Jason W.; Attaway, Stephen W.; Karelitz, David B.

The 9/30/2008 ASC Level 2 Post-Processing V&V Milestone (Milestone 2843) contains functionality required by the user community for certain verification and validation tasks. These capabilities include fragment detection from CTH simulation data, fragment characterization and analysis, and fragment sorting and display operations. The capabilities were tested extensively both on sample and actual simulations. In addition, a number of stretch criteria were met including a comparison between simulated and test data, and the ability to output each fragment as an individual geometric file.

More Details
TYPE SAND Report YEAR 2008
OSTIDOI

Large scale visualization on the Cray XT3 using ParaView

Moreland, Kenneth D.; Rogers, David R.

Post-processing and visualization are key components to understanding any simulation. Porting ParaView, a scalable visualization tool, to the Cray XT3 allows our analysts to leverage the same supercomputer they use for simulation to perform post-processing. Visualization tools traditionally rely on a variety of rendering, scripting, and networking resources; the challenge of running ParaView on the Lightweight Kernel is to provide and use the visualization and post-processing features in the absence of many OS resources. We have successfully accomplished this at Sandia National Laboratories and the Pittsburgh Supercomputing Center.

More Details
TYPE Conference YEAR 2008
OSTI

Massive graph visualization : LDRD final report

Moreland, Kenneth D.; Wylie, Brian N.

Graphs are a vital way of organizing data with complex correlations. A good visualization of a graph can fundamentally change human understanding of the data. Consequently, there is a rich body of work on graph visualization. Although there are many techniques that are effective on small to medium sized graphs (tens of thousands of nodes), there is a void in the research for visualizing massive graphs containing millions of nodes. Sandia is one of the few entities in the world that has the means and motivation to handle data on such a massive scale. For example, homeland security generates graphs from prolific media sources such as television, telephone, and the Internet. The purpose of this project is to provide the groundwork for visualizing such massive graphs. The research provides for two major feature gaps: a parallel, interactive visualization framework and scalable algorithms to make the framework usable to a practical application. Both the frameworks and algorithms are designed to run on distributed parallel computers, which are already available at Sandia. Some features are integrated into the ThreatView{trademark} application and future work will integrate further parallel algorithms.

More Details
TYPE SAND Report YEAR 2007
OSTIDOI

Post-processing V&V level II ASC milestone (2360) results

Moreland, Kenneth D.; Chavez, Elmer A.; Weirs, Vincent G.; Brunner, Thomas A.; Trucano, Timothy G.; Karelitz, David B.

The 9/30/2007 ASC Level 2 Post-Processing V&V Milestone (Milestone 2360) contains functionality required by the user community for certain verification and validation tasks. These capabilities include loading of edge and face data on an Exodus mesh, run-time computation of an exact solution to a verification problem, delivery of results data from the server to the client, computation of an integral-based error metric, simultaneous loading of simulation and test data, and comparison of that data using visual and quantitative methods. The capabilities were tested extensively by performing a typical ALEGRA HEDP verification task. In addition, a number of stretch criteria were met including completion of a verification task on a 13 million element mesh.

More Details
TYPE SAND Report YEAR 2007
OSTIDOI

A fast high accuracy volume renderer for unstructured data

Proceedings - IEEE Symposium on Volume Visualization and Graphics 2004. VolVis 2004

Moreland, Kenneth D.; Angel, Edward

In this paper, we describe an unstructured mesh volume renderer. Our renderer is interactive and accurately integrates light intensity an order of magnitude faster than previous methods. We employ a projective technique that takes advantage of the expanded programmability of the latest 3D graphics hardware. We also analyze an optical model commonly used for scientific volume rendering and derive a new method to compute it that is very accurate but computationally feasible in real time. We demonstrate a system that can accurately produce a volume rendering of an unstructured mesh with a first-order approximation to any classification method. Furthermore, our system is capable of rendering over 300 thousand tetrahedra per second yet is independent of the classification scheme used. © 2004 IEEE.

More Details
TYPE Conference YEAR 2004
ScopusOSTI
Results 201–313 of 313
Results 201–313 of 313