NA-ASC-500-07—Issue 2
January 2007
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The View from HQ
by Dimitri Kusnezov
Sitting in airports and planes is risky beyond the obvious dangers now in the news. Uninterrupted time to think may lead to new ideas. Instinct instructs us that when we hear Washington has some new ideas, the result must be bad. After all, ideas suggest change, which is inherently disruptive.
Successful Completion of ASC Purple Integration Impresses Review Panel
The fiscal year 2007 Level 1 Milestone to provide a 100-teraFLOPs platform environment supporting the tri-laboratory Directed Stockpile Work and Campaign simulation requirements was met with flying colors, as determined by a nine-member review panel composed of representatives from academia, the Department of Defense, the Department of Energy, and the National Nuclear Security Administration (NNSA) tri-laboratory community.
2006 Gordon Bell Prizes Awarded to Lawrence Livermore’s BlueGene/L Simulations
A large-scale electronic structure simulation of the heavy metal molybdenum conducted on the world’s fastest supercomputer, BlueGene/L, earned a team led by a former and current Lawrence Livermore National Laboratory (LLNL) scientists the 2006 Gordon Bell Prize for “peak performance.”
Los Alamos Completes First-of-Its-Kind Physics Code Assessment
A comprehensive verification and validation (V&V) assessment of a coupled-physics, primary burn code was completed at Los Alamos National Laboratory (LANL) in September. The code evaluation entailed comparisons of simulation results with theory and data, as well as extensive spatial and temporal convergence analyses. Single-physics test problems included problems from the Tri-Laboratory Test Suite such as the Noh and Sedov problems for hydrodynamics and the Sood-Forster problems for neutronics. New test problems were developed for radiation transport. Integral-physics test problems included selected problems from the JOWOG 42 suite among others. Separate effects test validation efforts concentrated on various criticality experiments. Validation of integrated simulation capabilities focused on Nevada Test Site results for a specific, well-instrumented event.
Critical Level 1 Verification & Validation Milestone Completed
An external review panel convened at ASC headquarters on December 5, 2006, to review completion evidence for a FY06 Level 1 Milestone to “deliver advanced ASC physics and engineering simulation capabilities to support the W76 and W80 LEP/certification.” Sandia’s contribution to the milestone consisted of (1) validating fire model predictions of heat flux to a weapon; (2) quantifying weapon safety margins and uncertainty in fire environments; (3) determining adequacy of arming, fuzing & firing (AF&F) assembly response predictions in a hostile blast environment. A Level 2 Milestone was completed in each of these areas. The panel concurred that the milestone had been successfully completed.
New Verification Analyses Method Developed
Los Alamos scientists Trevor Tippets, Frank Timmes, Jim Kamm, and Jerry Brock recently completed an initial exploration of a new method that performs verification analyses on complex multi-physics problems where an exact solution is unknown. The new method uses an optimization technique to estimate the exact solution in tandem with a self-consistent convergence rate. Unlike previous efforts, their new method allows for oscillatory convergence, which is observed to occur near shock fronts or material discontinuities. This step in technology is key to bridging the gap between analytical test problems and highly complex applications.
Award Winning Data Analysis Toolkit Released
It is difficult for computers to understand a simple thing like a tear in a sheet of metal. Standard data visualization techniques do not do the job, either, as material failures like tears may happen anywhere in a simulation. With massive datasets, the problem becomes much worse. There could be thousands of features that an analyst is interested in. How can we harness computation to help with this problem?
Truchas Software Applications Extended within Complex
As part of the ASC Engineering Verification and Validation (V&V) Project, the Los Alamos casting simulation software Truchas has been assessed for extending its application to other problems such as welding within the DOE Nuclear Weapons Complex.
Xyce Electrical Modeling and Simulation to Support Weapons Qualification
In FY07, the Xyce circuit modeling application was used to generate simulation results in support of weapon components qualification efforts. To provide the greatest impact to qualification, the simulations focused on performance issues surrounding critical electronic subsystems. The circuit model has been enhanced to simulate relevant realistic scenarios by adding parasitic elements and initial conditions. The simulations provide additional qualification evidence by confirming design margins, giving access to circuit response measures not available during tests, and allowing for simulation of realistic hostile radiation scenarios that cannot be tested. The simulation results show good agreement with available test data, and validation efforts are under way in FY07, including several novel validation experimental activities.
An Improved H-curl Algebraic Multigrid Solver for Z-pinch Simulations
Sandia’s ML solver team has resolved an extremely challenging technical issue associated with the solution of singular and ill-conditioned H(curl) matrices for ALEGRA-HEDP Z-pinch simulations.
Load Balancing Work Receives Best Paper Award
Researchers from Sandia and Ohio State University were awarded the Best Paper award in the Algorithms track of the 2007 International Parallel and Distributed Processing Symposium (IPDPS). The paper, Dynamic Load Balancing for Adaptive Scientific Computations via Hypergraph Repartitioning, presents a novel algorithm for redistributing data in adaptive parallel simulations. Authors are Erik Boman, Karen Devine, Robert Heaphy, and Lee Ann Fisk Riesen of Sandia, and Umit Catalyurek and Doruk Bozdag of the Ohio State University.
Sixth Annual Nuclear Weapons Engineering Analysis Conference (NWEAC)
Sandia National Laboratories hosted the sixth annual Nuclear Weapons Engineering Analysis Conference at Monterey, CA, on September 5-8, 2006. Approximately 70 engineering analysts from Sandia, Los Alamos, Lawrence Livermore, Kansas City Plant, and Y-12 met to discuss their respective nuclear weapons engineering simulations.
Los Alamos Hosts Tri-Lab V&V Workshop
Beginning Tuesday, January 9, 2007 and ending with a half-day on Friday, January 12, the ASC Verification and Validation (V&V) Workshop was held at Los Alamos, with participation limited by invitation to tri-lab V&V managers. After an introductory talk by Dimitri Kusnezov, the workshop began with the following topical areas: Primary Validation, Thermonuclear Application Validation, Engineering V&V, Code and Calculation Verification, Uncertainty Quantification, Tri-Lab Test Suites, Data Analysis, Software Quality Engineering (SQE), and others.
BlueGene/L Is Still the Fastest Computer in the World
The 28th TOP500 List was released in Tampa, FL, during SuperComputing 2006. On the new list, the BlueGene/L system retains the No. 1 spot with a Linpack performance of 280.6 teraFLOPs.
Red Storm Ranks No. 2 on Top 500 List
When the Top500 supercomputer list was announced at Supercomputing 2006, Red Storm placed second overall, and first among the general-purpose high-end computer systems that are useful for a broad range of the ASC portfolio of engineering and scientific analysis codes. Its Linpack performance is 101.4 teraFLOPs.
Between August and October 2006, Sandia and Cray successfully upgraded Red Storm by integrating a 5th row to increase the number of compute nodes from 10,368 to 12,960. The single core 2.0 GHz AMD Opteron processors were exchanged for dual core 2.4 GHz processors, and the initial SeaStar 1.2 was exchanged for SeaStar 2.1 NIC/Router interconnect chips—a change that effectively doubled the bandwidth performance of the interconnect sub-system. Sandia modified the Red Storm lightweight kernel operating system to provide a simple method for using the second core on each compute node for Message Passing Interface (MPI) applications. These combined hardware and software changes increased the measured Linpack performance from 36.19 teraFLOPs to 101.4 teraFLOPs.
Illustration of newly upgraded Red Storm
ASC Booth at SC06 Conference Demonstrates NNSA’s Achievements in High Performance Computing
With a theme of “Predictive Simulation with Confidence,” the ASC booth at SC06 once again presented ASC’s many achievements at the International Conference on High-Performance Computing, Networking, Data Storage, and Analysis. Sponsored by the Association for Computing Machinery (ACM) and the Institute of Electrical and Electronics Engineers (IEEE) Computer Society, this year’s conference was held in Tampa, FL, from November 11 to 17th.
IBM and BlueGene/L Continue Domination of HPCC Competition at SC06
For the second year, IBM and BlueGene/L dominated the High Performance Computing Challenge (HPCC) competition at the annual SuperComputing Conference (SC06). The DOE/NNSA/Lawrence Livermore National Laboratory team, using IBM’s BlueGene/L system, once again swept all four Class 1 (best performance) benchmark awards, proving BlueGene/L’s ability to solve a wide range of computational problems. The four Class 2 productivity awards were split between MIT, IBM, The MathWorks, and the Russian People Friendship University.
Sandia’s ASC Russia Program Hosts Russian Collaborators
A group of Russian scientists from the Russian Academy of Sciences’ Institute of Problems in Mechanical Engineering in St. Petersburg and its Institute of High Energy Densities in Moscow attended the first of two ASC-supported annual project reviews of the Russia Science and Technology Program.
TSF Team Honored with DOE Project Management Award
The Terascale Simulation Facility (TSF) Project at Lawrence Livermore National Lab has recently won the DOE Secretary’s Project Management Award of Achievement.
The Project Management Awards are presented annually to three teams that demonstrate outstanding performance based on overall management and successful completion of a project.
Sandia Wins Award for Red Storm Video
A video showcasing the Red Storm Supercomputer at Sandia National Laboratories has received a Finalist Award in the prestigious 2007 New York Festivals International Film and Video Competition in the Mathematics and Computer Science Category. The video, titled “Red Storm Visualization Tour,” was produced by a Sandia team to provide an option to physical tours of the supercomputer. Actual scientific simulations performed on Red Storm are interspersed with creative animations and dramatic flyovers of the computer to make the experience better than a walk-through tour in many ways.
The New York Festivals seeks to recognize “The World’s Best Work” in informational, educational and industrial film productions and corporate video. The competition also covers short film, feature-length film, and home videos. Now approaching its 50th anniversary, the Film & Video Awards sees entries from over 30 countries around the world. Entries are judged by panels of international award winning creatives who are recognized as leaders in their respective fields.
Sandia team members involved in the production of the video include John Zepper, John Noe, Constantine Pavlakos, Bob Ballance, Regina Valenzuela, Jon Goldman, Lisa Ice, Patricia Crossno, and David Karelitz.
Awards will be presented at a ceremony in New York City on February 2, 2007.
ASC Salutes
Editor’s note: Each quarter, the ASC Program will feature the outstanding contributions of one of its numerous tri-lab scientists, engineers, and administrators. This month, we proudly present Hank Childs.
Barely thirty years old, Computer Scientist Henry (Hank) R. Childs has already won an R&D 100 award and is now part of a team that will bridge high performance computing visualization efforts between the Department of Energy’s National Nuclear Security Administration and Office of Science.
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