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Performance and Algorithms Research
Performance and Algorithms Research

Publications

Over the years, researchers in the Performance and Algorithms Research Group have codified their research into papers that have been published in a variety of journals or conference proceedings.  Below is a sampling of our recent work.

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2024

Xuan Jiang, Raja Sengupta, James Demmel, Samuel Williams, "Large scale multi-GPU based parallel traffic simulation for accelerated traffic assignment and propagation", Transportation Research Part C: Emerging Technologies, December 2024, 169:104873, doi: 10.1016/j.trc.2024.104873

Nan Ding, Brian Austin, Yang Liu, Neil Mehta, Steven Farrell, Johannes P. Blaschke, Leonid Oliker, Hai Ah Nam, Nicholas J. Wright, Samuel Williams, "A Workflow Roofline Model for End-to-End Workflow Performance Analysis", Supercomputing (SC), November 2024,

Shashank Subramanian, Ermal Rrapaj, Peter Harrington, Smeet Chheda, Steven Farrell, Brian Austin, Samuel Williams, Nicholas Wright, Wahid Bhimji, "Comprehensive Performance Modeling and System Design Insights for Foundation Models", Performance Modeling, Benchmarking, and Simulation (PMBS), November 2024,

Brian Austin, Dhruva Kulkarni, Brandon Cook, Samuel Williams, Nicholas J. Wright, "System-Wide Roofline Profiling - a Case Study on NERSC’s Perlmutter Supercomputer", Performance Modeling, Benchmarking, and Simulation (PMBS), November 2024,

Oscar Antepara, Samuel Williams, Hans Johansen, Mary Hall, "High-Performance, Scalable Geometric Multigrid via Fine-Grain Data Blocking for GPUs", Performance, Portability & Productivity in HPC (P3HPC), November 10, 2024,

Oscar Antepara, Samuel Williams, Max Carlson, Jerry Watkins, "Performance Portable Optimizations of an Ice-sheet Modeling Code on GPU-supercomputers", Performance, Portability & Productivity in HPC (P3HPC), November 2024,

Sterling Smith, Zichuan Anthony Xing, Torrin Bechtel, Severin Denk, Earl DeShazer, Orso Meneghini, Tom Neiser, Laurie Stephey, Oscar Antepara, Christopher Mitchell Clark, Eli Dart, Pengfei Ding, Sean Flanagan, Raffi Nazikian, David Schissel, Christine Simpson, Nicholas Tyler, Thomas D. Uram, Samuel Williams, "Expediting Higher Fidelity Plasma State Reconstructions for the DIII-D National Fusion Facility Using Leadership Class Computing Resources", Extreme-Scale Experiment-in-the-Loop Computing (XLOOP), November 2024,

Mahesh Lakshminarasimhan, Oscar Antepara, Tuowen Zhao, Benjamin Sepanski, Protonu Basu, Hans Johansen, Mary Hall, Samuel Williams, "Bricks: A high-performance portability layer for computations on block-structured grids", The International Journal of High Performance Computing Applications (IJHPCA), August 19, 2024, doi: 10.1177/1094342024126828

Mahesh Lakshminarasimhan, Mary Hall, Samuel Williams, Oscar Antepara, "BrickDL: Graph-Level Optimizations for DNNs with Fine-Grained Data Blocking on GPUs", Proceedings of the 53rd International Conference on Parallel Processing (ICPP), August 12, 2024,

Nan Ding, Pieter Maris, Hai Ah Nam, Taylor Groves, Muaaz Gul Awan, LeAnn Lindsey, Christopher Daley, Oguz Selvitopi, Leonid Oliker, Nicholas Wright, Samuel Williams, "Evaluating the potential of disaggregated memory systems for HPC applications", Concurrency and Computation, Practice and Experience (CCPE), May 2024, doi: https://doi.org/10.1002/cpe.8147

2023

Oscar Antepara, Hans Johansen, Samuel Williams, Tuowen Zhao, Samantha Hirsch, Priya Goyal, Mary Hall, "Performance portability evaluation of blocked stencil computations on GPUs", International Workshop on Performance, Portability & Productivity in HPC (P3HPC), November 2023,

Oscar Antepara, Samuel Williams, Scott Kruger, Torrin Bechtel, Joseph McClenaghan, Lang Lao, "Performance-Portable GPU Acceleration of the EFIT Tokamak Plasma Equilibrium Reconstruction Code", Workshop on Accelerator Programming and Directives (WACCPD), November 2023,

Yang Liu, Nan Ding, Piyush Sao, Samuel Williams, Xiaoye Sherry Li, "Unified Communication Optimization Strategies for Sparse Triangular Solver on CPU and GPU Clusters", Supercomputing (SC), November 2023,

Nan Ding, Muhammad Haseeb, Taylor Groves, Samuel Williams, "Evaluating the Performance of One-sided Communication on CPUs and GPUs", 2023 International Workshop on Performance, Portability & Productivity in HPC, November 12, 2023,

Samuel Williams, Introduction to the Roofline Model, ECP Annual Meeting, February 8, 2023,

2022

Nan Ding, Samuel Williams, Hai Ah Nam, Taylor Groves, Muaaz Gul Awan, Christopher Delay, Oguz Selvitopi, Leonid Oliker, Nicholas Wright, "Methodology for Evaluating the Potential of Disaggregated Memory Systems", RESDIS, https://resdis.github.io/ws/2022/sc/, November 18, 2022,

Taylor Groves, Chris Daley, Rahulkumar Gayatri, Hai Ah Nam, Nan Ding, Lenny Oliker, Nicholas J. Wright, Samuel Williams, "A Methodology for Evaluating Tightly-integrated and Disaggregated Accelerated Architectures", PMBS, November 2022,

Benjamin Sepanski, Tuowen Zhao, Hans Johansen, Samuel Williams, "Maximizing Performance Through Memory Hierarchy-Driven Data Layout Transformations", MCHPC, November 2022,

K. Ibrahim, L. Oliker,, "Preprocessing Pipeline Optimization for Scientific Deep-Learning Workloads", IPDPS 22, June 3, 2022,

Samuel Williams, Introduction to the Roofline Model, ECP Annual Meeting, May 2022,

Neil Mehta, Roofline on NVIDIA at NERSC, ECP Annual Meeting, May 2022,

JaeHyuk Kwack, ROOFLINE PERFORMANCE ANALYSIS W/ INTEL ADVISOR ON INTEL CPUS & GPUS, ECP Annual Meeting, May 2022,

2021

Khaled Z. Ibrahim, Tan Nguyen, Hai Ah Nam, Wahid Bhimji, Steven Farrell, Leonid Oliker, Michael Rowan, Nicholas J. Wright, Samuel Williams, "Architectural Requirements for Deep Learning Workloads in HPC Environments", (BEST PAPER), Performance Modeling, Benchmarking, and Simulation (PMBS), November 2021,

Marco Siracusa, Emanuele Del Sozzo, Marco Rabozzi, Lorenzo Di Tucci, Samuel Williams, Donatella Sciuto, Marco Domenico Santambrogio, "A Comprehensive Methodology to Optimize FPGA Designs via the Roofline Model", Transactions on Computers (TC), September 2021, doi: 10.1109/TC.2021.3111761

Tan Nguyen, Colin MacLean, Marco Siracusa, Douglas Doerfler, Nicholas J. Wright, Samuel Williams, "FPGA‐based HPC accelerators: An evaluation on performance and energy efficiency", CCPE, August 22, 2021, doi: 10.1002/cpe.6570

Nan Ding, Muaaz Awan, Samuel Williams, "Instruction Roofline: An insightful visual performance model for GPUs", CCPE, August 4, 2021, doi: 10.1002/cpe.6591

Nan Ding, Yang Liu, Samuel Williams, Xiaoye S. Li, "A Message-Driven, Multi-GPU Parallel Sparse Triangular Solver", SIAM Conference on Applied and Computational Discrete Algorithms (ACDA21), July 19, 2021,

Charlene Yang, Yunsong Wang, Thorsten Kurth, Steven Farrell, Samuel Williams, "Hierarchical Roofline Performance Analysis for Deep Learning Applications", Intelligent Computing, LNNS, July 15, 2021, doi: 10.1007/978-3-030-80126-7

Giulia Guidi, Marquita Ellis, Daniel Rokhsar, Katherine Yelick, Aydın Buluç, "BELLA: Berkeley Efficient Long-Read to Long-Read Aligner and Overlapper", SIAM Conference on Applied and Computational Discrete Algorithms (ACDA21), 2021, doi: 10.1101/464420

Douglas Doerfler, Farzad Fatollahi-Fard, Colin MacLean, Tan Nguyen, Samuel Williams, Nicholas J. Wright, Marco Siracusa, "Experiences Porting the SU3_Bench Microbenchmark to the Intel Arria 10 and Xilinx Alveo U280 FPGAs", International Workshop on OpenCL (iWOCL), April 2021, doi: 10.1145/3456669.3456671

Samuel Williams, Introduction to the Roofline Model, ECP Annual Meeting, April 2021,

Samuel Williams, Roofline Analysis on NVIDIA GPUs, ECP Annual Meeting, April 2021,

Khaled Ibrahim, Roofline on GPUs (advanced topics), ECP Annual Meeting, April 2021,

Tuowen Zhao, Mary Hall, Hans Johansen, Samuel Williams, "Improving Communication by Optimizing On-Node Data Movement with Data Layout", PPoPP, February 2021,

2020

Anastasiia Butko, George Michelogiannakis, Samuel Williams, Costin Iancu, David Donofrio, John Shalf, Jonathan Carter, Irfan Siddiqi, "Understanding Quantum Control Processor Capabilities and Limitations through Circuit Characterization", IEEE Conference on Rebooting Computing (ICRC), December 2020,

Tan Nguyen, Samuel Williams, Marco Siracusa, Colin MacLean, Douglas Doerfler, Nicholas J. Wright, "The Performance and Energy Efficiency Potential of FPGAs in Scientific Computing", (BEST PAPER) Performance Modeling, Benchmarking, and Simulation of High Performance Computer Systems (PMBS), November 2020,

Yunsong Wang, Charlene Yang, Steven Farrell, Yan Zhang, Thorsten Kurth, Samuel Williams, "Time-Based Roofline for Deep Learning Performance Analysis", Deep Learning on Supercomputing (DLonSC), November 2020,

Samuel Williams, Introduction to the Roofline Model, Supercomputing (SC), November 2020,

Marco Siracusa, Marco Rabozzi, Emanuele Del Sozzo, Lorenzo Di Tucci, Samuel Williams, Marco D. Santambrogio, "A CAD-based methodology to optimize HLS code via the Roofline model", International Conference on Computer Aided Design (ICCAD), November 2020, doi: 10.1145/3400302.3415730

Christopher Daley, Hadia Ahmed, Samuel Williams, Nicholas Wright, "A case study of porting HPGMG from CUDA to OpenMP target offload", The International Workshop on OpenMP (IWOMP), September 2020,

Samuel Williams, The Roofline Model: A Bridge between Computer Science, Applied Math, and Computational Science, SciDAC Meeting, July 2020,

Samuel Williams, Introduction to the Roofline Model, NERSC NVIDIA Roofline Hackathon, July 2020,

Samuel Williams, Introduction to the Roofline Model, NERSC GPU For Science Workshop, July 2020,

Samuel Williams, Charlene Yang, Yunsong Wang, Roofline Performance Modeling for HPC and Deep Learning Applications, NVIDIA GPU Technology Conference (GTC), March 2020,

Nan Ding, Samuel Williams, Yang Liu, Xiaoye S. Li, "Leveraging One-Sided Communication for Sparse Triangular Solvers", 2020 SIAM Conference on Parallel Processing for Scientific Computing, February 14, 2020,

Samuel Williams, Introduction to the Roofline Model, ECP Annual Meeting, February 2020,

Charlene Yang, Hierarchical Roofline Analysis on GPUs, ECP Annual Meeting, February 2020,

Samuel Williams, Roofline on GPUs (Advanced Topics), ECP Annual Meeting, February 2020,

Charlene Yang, Hierarchical Roofline Analysis on CPUs, ECP Annual Meeting, February 2020,

Jack Deslippe, Guiding Optimization with the Roofline Model, ECP Annual Meeting, February 2020,

T Groves, B Brock, Y Chen, KZ Ibrahim, L Oliker, NJ Wright, S Williams, K Yelick, "Performance Trade-offs in GPU Communication: A Study of Host and Device-initiated Approaches", Proceedings of PMBS 2020: Performance Modeling, Benchmarking and Simulation of High Performance Computer Systems, Held in conjunction with SC 2020: The International Conference for High Performance Computing, Networking, Storage and Analysis, January 2020, 126--137, doi: 10.1109/PMBS51919.2020.00016

2019

Tuowen Zhao, Mary Hall, Samuel Williams, Hans Johansen, "Exploiting Reuse and Vectorization in Blocked Stencil Computations on CPUs and GPUs", Supercomputing (SC), November 2019,

Nan Ding, Samuel Williams, "An Instruction Roofline Model for GPUs", Performance Modeling, Benchmarking, and Simulation (PMBS), BEST PAPER AWARD, November 18, 2019,

Nan Ding, Samuel Williams, An Instruction Roofline Model for GPUs, Performance Modeling, Benchmarking, and Simulation (PMBS), BEST PAPER AWARD, November 18, 2019,

Khaled Ibrahim, Samuel Williams, Leonid Oliker, "Performance Analysis of GPU Programming Models using the Roofline Scaling Trajectories", International Symposium on Benchmarking, Measuring and Optimizing (Bench), BEST PAPER AWARD, November 2019,

Charlene Yang, Thorsten Kurth, Samuel Williams, "Hierarchical Roofline analysis for GPUs: Accelerating performance optimization for the NERSC-9 Perlmutter system", Concurrency and Computation: Practice and Experience (CCPE), August 2019, doi: 10.1002/cpe.5547

Nan Ding, Samuel Williams, Sherry Li, Yang Liu, "Leveraging One-Sided Communication for Sparse Triangular Solvers", SciDAC19, July 18, 2019,

Samuel Williams, Charlene Yang, Khaled Ibrahim, Thorsten Kurth, Nan Ding, Jack Deslippe, Leonid Oliker, "Performance Analysis using the Roofline Model", SciDAC PI Meeting, July 2019,

Charlene Yang, Thorsten Kurth, Samuel Williams, "Hierarchical Roofline Analysis for GPUs: Accelerating Performance Optimization for the NERSC-9 Perlmutter System", Cray User Group (CUG), May 2019,

Wenjing Ma, Yulong Ao, Chao Yang, Samuel Williams, "Solving a trillion unknowns per second with HPGMG on Sunway TaihuLight", Cluster Computing, May 2019, doi: 10.1007/s10586-019-02938-w

Charlene Yang, Samuel Williams, Performance Analysis of GPU-Accelerated Applications using the Roofline Model, GPU Technology Conference (GTC), March 2019,

Samuel Williams, Performance Modeling and Analysis, CS267 Lecture, University of California at Berkeley, February 14, 2019,

Samuel Williams, Introduction to the Roofline Model, Roofline Tutorial, ECP Annual Meeting, January 2019,

Samuel Williams, Roofline on CPU-based Systems, Roofline Tutorial, ECP Annual Meeting, January 2019,

2018

Tuowen Zhao, Samuel Williams, Mary Hall, Hans Johansen, "Delivering Performance Portable Stencil Computations on CPUs and GPUs Using Bricks", International Workshop on Performance, Portability and Productivity in HPC (P3HPC), November 2018,

Charlene Yang, Rahulkumar Gayatri, Thorsten Kurth, Protonu Basu, Zahra Ronaghi, Adedoyin Adetokunbo, Brian Friesen, Brandon Cook, Douglas Doerfler, Leonid Oliker, Jack Deslippe, Samuel Williams, "An Empirical Roofline Methodology for Quantitatively Assessing Performance Portability", International Workshop on Performance, Portability and Productivity in HPC (P3HPC), November 2018,

Nan Ding, Victor W Lee, Wei Xue, Weimin Zheng, "Understanding Potential Performance Issues Using Resource-based Alongside Time Models", SC'18, November 13, 2018,

Hongzhang Shan, Samuel Williams, Calvin W. Johnson, "Improving MPI Reduction Performance for Manycore Architectures with OpenMP and Data Compression", Performance Modeling, Benchmarking and Simulation of High Performance Computer Systems (PMBS), November 2018,

Samuel Williams, Introduction to the Roofline Model, Supercomputing, November 2018,

Samuel Williams, Roofline on Manycore and Accelerated Systems, ModSim, August 2018,

Samuel Williams, Parallelism and Performance, MolSSI Summer School, August 2018,

Khaled Ibrahim, Samuel Williams, Leonid Oliker, "Roofline Scaling Trajectories: A Method for Parallel Application and Architectural Performance Analysis", HPCS Special Session on High Performance Computing Benchmarking and Optimization (HPBench), July 2018,

Tuomas Koskela, Zakhar Matveev, Charlene Yang, Adetokunbo Adedoyin, Roman Belenov, Philippe Thierry, Zhengji Zhao, Rahulkumar Gayatri, Hongzhang Shan, Leonid Oliker, Jack Deslippe, Ron Green, and Samuel Williams, "A Novel Multi-Level Integrated Roofline Model Approach for Performance Characterization", ISC, June 2018,

Charlene Yang, Brian Friesen, Thorsten Kurth, Brandon Cook, Samuel Williams, "Toward Automated Application Profiling on Cray Systems", Cray User Group (CUG), May 2018,

Ariful Azad, Georgios A. Pavlopoulos, Christos A. Ouzounis, Nikos C. Kyrpides, Aydin Buluç, "HipMCL: A high-performance parallel implementation of the Markov cluster algorithm for large scale networks", Nucleic Acids Research, April 2018,

Tuowen Zhao, Mary Hall, Protonu Basu, Samuel Williams, Hans Johansen, "SIMD code generation for stencils on brick decompositions", Proceedings of the 23rd ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming (PPoPP), February 2018,

Samuel Williams, Introduction to the Roofline Model, ECP Annual Meeting, February 8, 2018,

Samuel Williams, Advisor Hand-On: Stencil Example, ECP Annual Meeting, February 8, 2018,

Protonu Basu, Using Empirical Roofline Toolkit and Nvidia nvprof, ECP Annual Meeting, February 8, 2018,

Charlene Yang, Intel Advisor on Cori, ECP Annual Meeting, February 8, 2018,

Charlene Yang, LIKWID at NERSC, ECP Annual Meeting, February 8, 2018,

Jack Deslippe, Guiding Optimization on KNL with the Roofline Model, ECP Annual Meeting, February 8, 2018,

Nan Ding, WeiXue, Zhenya Song, Haohuan Fub, Shiming Xu, WeiminZhenga, "An automatic performance model-based scheduling tool for coupled climate system models", JPDC, January 31, 2018,

Samuel Williams, Performance Modeling and Analysis, CS267 lecture, University of California at Berkeley, January 30, 2018,

2017

Samuel Williams, Introduction to the Roofline Model, Roofline Training, November 2017,

Yang You, Aydin Buluc, James Demmel, "Scaling deep learning on GPU and Knights Landing clusters", Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis (SC'17), 2017,

Haohuan Fu, Junfeng Liao, Nan Ding, Xiaohui Duan, Lin Gan,Yishuang Liang,Xinliang Wang,Jinzhe Yang,Yan Zheng,Weiguo Liu,Lanning Wang,Guangwen Yang, "Redesigning CAM-SE for peta-scale climate modeling performance and ultra-high resolution on Sunway TaihuLight (ACM Gordon Bell Prize Finalist)", SC'17, November 12, 2017,

Philip C. Roth, Hongzhang Shan, David Riegner, Nikolas Antolin, Sarat Sreepathi, Leonid Oliker, Samuel Williams, Shirley Moore, Wolfgang Windl, "Performance Analysis and Optimization of the RAMPAGE Metal Alloy Potential Generation Software", SIGPLAN International Workshop on Software Engineering for Parallel Systems (SEPS), October 2017,

Jack Deslippe, Doug Doerfler, Brandon Cook, Tareq Malas, Samuel Williams, Sudip Dosanjh, "Optimizing science applications for the Cori, Knights Landing, System at NERSC", Advances in Parallel Computing, New Frontiers in High Performance Computing and Big Data, August 2017, 30, doi: 10.3233/978-1-61499-816-7-235

Hongzhang Shan, Samuel Williams, Calvin Johnson, Kenneth McElvain, "A Locality-based Threading Algorithm for the Configuration-Interaction Method", Parallel and Distributed Scientific and Engineering Computing (PDSEC), June 2017,

Bryce Adelstein Lelbach, Hans Johansen, Samuel Williams, "Simultaneously Solving Swarms of Small Sparse Systems on SIMD Silicon", Parallel and Distributed Scientific and Engineering Computing (PDSEC), June 2017,

Brandon Cook, Thorsten Kurth, Brian Austin, Samuel Williams, Jack Deslippe, "Performance Variability on Xeon Phi", Intel Xeon Phi Users Group (IXPUG), June 2017,

Thorsten Kurth, William Arndt, Taylor Barnes, Brandon Cook, Jack Deslippe, Doug Doerfler, Brian Friesen, Yun (Helen) He, Tuomas Koskela, Mathieu Lobet, Tareq Malas, Leonid Oliker, Andrey Ovsyannikov, Samuel Williams, Woo-Sun Yang, and Zhengji Zhao, "Analyzing Performance of Selected NESAP Applications on the Cori HPC System", Intel Xeon Phi Users Group (IXPUG), June 2017,

Ariful Azad, Aydin Buluc, "Towards a GraphBLAS Library in Chapel", IPDPS Workshops, Orlando, FL, May 2017,

Aydin Buluc, Tim Mattson, Scott McMillan, Jose Moreira, Carl Yang, "Design of the GraphBLAS API for C", IEEE Workshop on Graph Algorithm Building Blocks, IPDPSW, 2017,

Ariful Azad, Aydin Buluc, "A work-efficient parallel sparse matrix-sparse vector multiplication algorithm", IEEE International Parallel & Distributed Processing Symposium (IPDPS), Orlando, FL, May 2017,

Nathan Zhang, Michael Driscoll, Armando Fox, Charles Markley, Samuel Williams, Protonu Basu, "Snowflake: A Lightweight Portable Stencil DSL", High-level Parallel Programming Models and Supportive Environments (HIPS), May 2017,

Bei Wang, Stephane Ethier, William Tang, Khaled Ibrahim, Kamesh Madduri, Samuel Williams, Leonid Oliker, "Modern Gyrokinetic Particle-in-cell Simulation of Fusion Plasmas on Top Supercomputers", International Journal of High-Performance Computing Applications (IJHPCA), May 2017, doi: https://doi.org/10.1177/1094342017712059

Protonu Basu, Samuel Williams, Brian Van Straalen, Leonid Oliker, Phillip Colella, Mary Hall, "Compiler-Based Code Generation and Autotuning for Geometric Multigrid on GPU-Accelerated Supercomputers", Parallel Computing (PARCO), April 2017, doi: 10.1016/j.parco.2017.04.002

Khaled Z. Ibrahim, Evgeny Epifanovsky, Samuel Williams, Anna I. Krylov, "Cross-scale efficient tensor contractions for coupled cluster computations through multiple programming model backends", Journal of Parallel and Distributed Computing (JPDC), February 2017, doi: 10.1016/j.jpdc.2017.02.010

Esmond Ng, Katherine J. Evans, Peter Caldwell, Forrest M. Hoffman, Charles Jackson, Kerstin Van Dam, Ruby Leung, Daniel F. Martin, George Ostrouchov, Raymond Tuminaro, Paul Ullrich, Stefan Wild, Samuel Williams, "Advances in Cross-Cutting Ideas for Computational Climate Science (AXICCS)", January 2017, doi: 10.2172/1341564

Ariful Azad, Mathias Jacquelin, Aydin Bulu\cc, Esmond G Ng, "The reverse Cuthill-McKee algorithm in distributed-memory", Parallel and Distributed Processing Symposium (IPDPS), 2017 IEEE International, January 2017, 22--31,

E Georganas, M Ellis, R Egan, S Hofmeyr, A Buluç, B Cook, L Oliker, K Yelick, "MerBench: PGAS benchmarks for high performance genome assembly", Proceedings of PAW 2017: 2nd Annual PGAS Applications Workshop - Held in conjunction with SC 2017: The International Conference for High Performance Computing, Networking, Storage and Analysis, 2017, 2017-Jan:1--4, doi: 10.1145/3144779.3169109

M Ellis, E Georganas, R Egan, S Hofmeyr, A Buluç, B Cook, L Oliker, K Yelick, "Performance characterization of de novo genome assembly on leading parallel systems", Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2017, 10417 LN:79--91, doi: 10.1007/978-3-319-64203-1_6

2016

S.V. Venkatakrishnan, Jeffrey Donatelli, Dinesh Kumar, Abhinav Sarje, Sunil K. Sinha, Xiaoye S. Li, Alexander Hexemer, "A Multi-slice Simulation Algorithm for Grazing-Incidence Small-Angle X-ray Scattering", Journal of Applied Crystallography, December 2016, 49-6, doi: 10.1107/S1600576716013273

Grazing-incidence small-angle X-ray scattering (GISAXS) is an important technique in the characterization of samples at the nanometre scale. A key aspect of GISAXS data analysis is the accurate simulation of samples to match the measurement. The distorted-wave Born approximation (DWBA) is a widely used model for the simulation of GISAXS patterns. For certain classes of sample such as nanostructures embedded in thin films, where the electric field intensity variation is significant relative to the size of the structures, a multi-slice DWBA theory is more accurate than the conventional DWBA method. However, simulating complex structures in the multi-slice setting is challenging and the algorithms typically used are designed on a case-by-case basis depending on the structure to be simulated. In this paper, an accurate algorithm for GISAXS simulations based on the multi-slice DWBA theory is presented. In particular, fundamental properties of the Fourier transform have been utilized to develop an algorithm that accurately computes the average refractive index profile as a function of depth and the Fourier transform of the portion of the sample within a given slice, which are key quantities required for the multi-slice DWBA simulation. The results from this method are compared with the traditionally used approximations, demonstrating that the proposed algorithm can produce more accurate results. Furthermore, this algorithm is general with respect to the sample structure, and does not require any sample-specific approximations to perform the simulations.

Mark Adams, Samuel Williams, HPGMG BoF - Introduction, HPGMG BoF, Supercomputing, November 2016,

Samuel Williams, HPGMG on the Knights Landing Processor, HPGMG BoF, Supercomputing, November 2016,

Samuel Williams, HPGMG Benchmark, Top500 BoF, Supercomputing, November 2016,

William Tang, Bei Wang, Stephane Ethier, Grzegorz Kwasniewski, Torsten Hoefler, Khaled Z. Ibrahim4, Kamesh Madduri, Samuel Williams, Leonid Oliker, Carlos Rosales-Fernandez, Tim Williams, "Extreme Scale Plasma Turbulence Simulations on Top Supercomputers Worldwide", Supercomputing, November 2016,

Taylor Barnes, Brandon Cook, Jack Deslippe, Douglas Doerfler, Brian Friesen, Yun (Helen) He, Thorsten Kurth, Tuomas Koskela, Mathieu Lobet, Tareq Malas, Leonid Oliker, Andrey Ovsyannikov, Abhinav Sarje, Jean-Luc Vay, Henri Vincenti, Samuel Williams, Pierre Carrier, Nathan Wichmann, Marcus Wagner, Paul Kent, Christopher Kerr, John Dennis, "Evaluating and Optimizing the NERSC Workload on Knights Landing", Performance Modeling, Benchmarking and Simulation of High Performance Computer Systems (PMBS), November 2016,

Haohuan Fu, Junfeng Liao, Wei Xue, Lanning Wang, Dexun Chen, Long Gu, Jinxiu Xu, Nan Ding, Xinliang Wang, Conghui He, Shizhen Xu, Yishuang Liang, Jiarui Fang, Yuanchao Xu, Weijie Zheng, etc., "Refactoring and optimizing the community atmosphere model (CAM) on the sunway taihulight supercomputer", SC'16, November 13, 2016,

Ariful Azad, Grey Ballard, Aydin Buluc, James Demmel, Laura Grigori, Oded Schwartz, Sivan Toledo, Samuel Williams, "Exploiting multiple levels of parallelism in sparse matrix-matrix multiplication", SIAM Journal on Scientific Computing, 38(6), C624–C651, November 2016, doi: 10.1137/15M104253X

Nicholas Chaimov, Khaled Z. Ibrahim, Samuel Williams, Costin Iancu, "Reaching Bandwidth Saturation Using Transparent Injection Parallelization", International Journal of High Performance Computing Applications (IJHPCA), November 2016, doi: 10.1177/1094342016672720

Hasan Metin Aktulga, Md. Afibuzzaman, Samuel Williams, Aydın Buluc, Meiyue Shao, Chao Yang, Esmond G. Ng, Pieter Maris, James P. Vary, "A High Performance Block Eigensolver for Nuclear Configuration Interaction Calculations", IEEE Transactions on Parallel and Distributed Systems (TPDS), November 2016, doi: 10.1109/TPDS.2016.2630699

Zhaoyi Meng, Alice Koniges, Yun (Helen) He, Samuel Williams, Thorsten Kurth, Brandon Cook, Jack Deslippe, and Andrea L. Bertozzi, "OpenMP Parallelization and Optimization of Graph-Based Machine Learning Algorithms", 12th International Workshop on OpenMP (iWOMP), October 2016, doi: 10.1007/978-3-319-45550-1_2

Pieter Ghysels, Xiaoye S. Li, François-Henry Rouet, Samuel Williams, Artem Napov, "An Efficient Multicore Implementation of a Novel HSS-Structured Multifrontal Solver Using Randomized Sampling", SIAM J. Sci. Comput. 38-5, pp. S358-S384, October 2016, doi: 10.1137/15M1010117

Jeremy Kepner, Peter Aaltonen, David Bader, Aydin Buluç, Franz Franchetti, John Gilbert, Dylan Hutchison, Manoj Kumar, Andrew Lumsdaine, Henning Meyerhenke, Scott McMillan, José Moreira, John Owens, Carl Yang, Marcin Zalewski, Timothy Mattson., "Mathematical foundations of the GraphBLAS", IEEE High Performance Extreme Computing (HPEC), September 1, 2016,

Abhinav Sarje, Xiaoye S Li, Nicholas Wright, "Achieving High Parallel Efficiency on Modern Processors for X-ray Scattering Data Analysis", International Workshop on Multicore Software Engineering at EuroPar, 2016,

Khaled Z. Ibrahim, Evgeny Epifanovsky, Samuel Williams, Anna I. Krylov, "Cross-scale Efficient Tensor Contractions for Coupled Cluster Computations Through Multiple Programming Model Backends (tech report version)", LBNL. - Report Number: LBNL-1005853, July 1, 2016, LBNL 1005853, doi: 10.2172/1274416

Ariful Azad, Bartek Rajwa, Alex Pothen, "flowVS: Channel-Speci c Variance Stabilization in Flow Cytometry", BMC Bioinformatics, June 2016,

Douglas Doerfer, Jack Deslippe, Samuel Williams, Leonid Oliker, Brandon Cook, Thorsten Kurth, Mathieu Lobet, Tareq Malas, Jean-Luc Vay, and Henri Vincenti, "Applying the Roofline Performance Model to the Intel Xeon Phi Knights Landing Processor", Intel Xeon Phi User Group Workshop (IXPUG), June 2016,

Ariful Azad, Aydın Buluç, "A matrix-algebraic formulation of distributed-memory maximal cardinality matching algorithms in bipartite graphs", Parallel Computing, June 2016,

Ariful Azad, Aydin Buluç, "Distributed-Memory Algorithms for Maximum Cardinality Matching in Bipartite Graphs", IEEE International Parallel & Distributed Processing Symposium (IPDPS), May 2016,

Ariful Azad, Aydın Buluç, Alex Pothen, "Computing Maximum Cardinality Matchings in Parallel on Bipartite Graphs via Tree-Grafting", IEEE Transactions on Parallel and Distributed Systems (TPDS), May 2016,

Abhinav Sarje, Douglas W. Jacobsen, Samuel W. Williams, Todd Ringler, Leonid Oliker, "Exploiting Thread Parallelism for Ocean Modeling on Cray XC Supercomputers", Cray User Group (CUG), London, UK, May 2016,

Abhinav Sarje, Exploiting Thread Parallelism for Ocean Modeling on Cray XC Supercomputers, Cray Users Group (CUG), May 12, 2016,

Ariful Azad, Aydın Buluç, Distributed-memory algorithms for cardinality matching using matrix algebra, SIAM Conference on Parallel Processing for Scientific Computing (PP), Paris, France, April 2016,

J. R. Jones, F.-H. Rouet, K. V. Lawler, E. Vecharynski, K. Z. Ibrahim, S. Williams, B. Abeln, C. Yang, C. W. McCurdy, D. J. Haxton, X. S. Li, T. N. Rescigno, "An efficient basis set representation for calculating electrons in molecules", Journal of Molecular Physics, 2016, doi: 10.1080/00268976.2016.1176262

The method of McCurdy, Baertschy, and Rescigno, J. Phys. B, 37, R137 (2004) is generalized to obtain a straightforward, surprisingly accurate, and scalable numerical representation for calculating the electronic wave functions of molecules. It uses a basis set of product sinc functions arrayed on a Cartesian grid, and yields 1 kcal/mol precision for valence transition energies with a grid resolution of approximately 0.1 bohr. The Coulomb matrix elements are replaced with matrix elements obtained from the kinetic energy operator. A resolution-of-the-identity approximation renders the primitive one- and two-electron matrix elements diagonal; in other words, the Coulomb operator is local with respect to the grid indices. The calculation of contracted two-electron matrix elements among orbitals requires only O(N log(N)) multiplication operations, not O(N^4), where N is the number of basis functions; N = n^3 on cubic grids. The representation not only is numerically expedient, but also produces energies and properties superior to those calculated variationally. Absolute energies, absorption cross sections, transition energies, and ionization potentials are reported for one- (He^+, H_2^+ ), two- (H_2, He), ten- (CH_4) and 56-electron (C_8H_8) systems.

The method of McCurdy, Baertschy, and Rescigno, J. Phys. B, 37, R137 (2004) is generalized to obtain a straightforward, surprisingly accurate, and scalable numerical representation for calculating the electronic wave functions of molecules. It uses a basis set of product sinc functions arrayed on a Cartesian grid, and yields 1 kcal/mol precision for valence transition energies with a grid resolution of approximately 0.1 bohr. The Coulomb matrix elements are replaced with matrix elements obtained from the kinetic energy operator. A resolution-of-the-identity approximation renders the primitive one- and two-electron matrix elements diagonal; in other words, the Coulomb operator is local with respect to the grid indices. The calculation of contracted two-electron matrix elements among orbitals requires only O(N log(N)) multiplication operations, not O(N^4), where N is the number of basis functions; N = n^3 on cubic grids. The representation not only is numerically expedient, but also produces energies and properties superior to those calculated variationally. Absolute energies, absorption cross sections, transition energies, and ionization potentials are reported for one- (He^+, H_2^+ ), two- (H_2, He), ten- (CH_4) and 56-electron (C_8H_8) systems.The method of McCurdy, Baertschy, and Rescigno, J. Phys. B, 37, R137 (2004) is generalized to obtain a straightforward, surprisingly accurate, and scalable numerical representation for calculating the electronic wave functions of molecules. It uses a basis set of product sinc functions arrayed on a Cartesian grid, and yields 1 kcal/mol precision for valence transition energies with a grid resolution of approximately 0.1 bohr. The Coulomb matrix elements are replaced with matrix elements obtained from the kinetic energy operator. A resolution-of-the-identity approximation renders the primitive one- and two-electron matrix elements diagonal; in other words, the Coulomb operator is local with respect to the grid indices. The calculation of contracted two-electron matrix elements among orbitals requires only O(N log(N)) multiplication operations, not O(N^4), where N is the number of basis functions; N = n^3 on cubic grids. The representation not only is numerically expedient, but also produces energies and properties superior to those calculated variationally. Absolute energies, absorption cross sections, transition energies, and ionization potentials are reported for one- (He^+, H_2^+ ), two- (H_2, He), ten- (CH_4) and 56-electron (C_8H_8) systems.

 

The method of McCurdy, Baertschy, and Rescigno, J. Phys. B, 37, R137 (2004) is generalized to obtain a straightforward, surprisingly accurate, and scalable numerical representation for calculating the electronic wave functions of molecules. It uses a basis set of product sinc functions arrayed on a Cartesian grid, and yields 1 kcal/mol precision for valence transition energies with a grid resolution of approximately 0.1 bohr. The Coulomb matrix elements are replaced with matrix elements obtained from the kinetic energy operator. A resolution-of-the-identity approximation renders the primitive one- and two-electron matrix elements diagonal; in other words, the Coulomb operator is local with respect to the grid indices. The calculation of contracted two-electron matrix elements among orbitals requires only O(N log(N)) multiplication operations, not O(N^4), where N is the number of basis functions; N = n^3 on cubic grids. The representation not only is numerically expedient, but also produces energies and properties superior to those calculated variationally. Absolute energies, absorption cross sections, transition energies, and ionization potentials are reported for one- (He^+, H_2^+ ), two- (H_2, He), ten- (CH_4) and 56-electron (C_8H_8) systems.The method of McCurdy, Baertschy, and Rescigno, J. Phys. B, 37, R137 (2004) is generalized to obtain a straightforward, surprisingly accurate, and scalable numerical representation for calculating the electronic wave functions of molecules. It uses a basis set of product sinc functions arrayed on a Cartesian grid, and yields 1 kcal/mol precision for valence transition energies with a grid resolution of approximately 0.1 bohr. The Coulomb matrix elements are replaced with matrix elements obtained from the kinetic energy operator. A resolution-of-the-identity approximation renders the primitive one- and two-electron matrix elements diagonal; in other words, the Coulomb operator is local with respect to the grid indices. The calculation of contracted two-electron matrix elements among orbitals requires only O(N log(N)) multiplication operations, not O(N^4), where N is the number of basis functions; N = n^3 on cubic grids. The representation not only is numerically expedient, but also produces energies and properties superior to those calculated variationally. Absolute energies, absorption cross sections, transition energies, and ionization potentials are reported for one- (He^+, H_2^+ ), two- (H_2, He), ten- (CH_4) and 56-electron (C_8H_8) systems.

Samuel Williams, Mark Adams, Brian Van Straalen, Performance Portability in Hybrid and Heterogeneous Multigrid Solvers, Copper Moutain, March 2016,

S Williams, D Patterson, L Oliker, J Shalf, K Yelick, The roofline model: A pedagogical tool for program analysis and optimization, 2008 IEEE Hot Chips 20 Symposium, HCS 2008, 2016, doi: 10.1109/HOTCHIPS.2008.7476531

P Koanantakool, A Azad, A Buluc, D Morozov, SY Oh, L Oliker, K Yelick, "Communication-Avoiding Parallel Sparse-Dense Matrix-Matrix Multiplication", Proceedings - 2016 IEEE 30th International Parallel and Distributed Processing Symposium, IPDPS 2016, January 2016, 842--853, doi: 10.1109/IPDPS.2016.117

H Shan, S Williams, Y Zheng, W Zhang, B Wang, S Ethier, Z Zhao, IEEE, "Experiences of Applying One-Sided Communication to Nearest-Neighbor Communication", PROCEEDINGS OF PAW 2016: 1ST PGAS APPLICATIONS WORKSHOP (PAW), January 2016, 17--24, doi: 10.1109/PAW.2016.008

2015

Abhinav Sarje, Particle Swarm Optimization, DUNE Wire-Cell Reconstruction Summit, December 2015,

Samuel Williams, X-TUNE, X-Stack PI Meeting, December 2015,

Samuel Williams, 4th Order HPGMG-FV Implementation, HPGMG BoF, Supercomputing, November 2015,

Vladimir Marjanovic, HPC Benchmarking, HPGMG BoF, Supercomputing, November 2015,

Hongzhang Shan, Kenneth McElvain, Calvin Johnson, Samuel Williams, W. Erich Ormand, "Parallel Implementation and Performance Optimization of the Configuration-Interaction Method", Supercomputing (SC), November 2015, doi: 10.1145/2807591.2807618

Ariful Azad, Aydin Buluc, "Distributed-Memory Algorithms for Maximal Cardinality Matching using Matrix Algebra", IEEE Cluster, Chicago, IL, September 2015,

Alex Druinsky, Pieter Ghysels, Xiaoye S. Li, Osni Marques, Samuel Williams, Andrew Barker, Delyan Kalchev, Panayot Vassilevski, "Comparative Performance Analysis of Coarse Solvers for Algebraic Multigrid on Multicore and Manycore Architectures", International Conference on Parallel Processing and Applied Mathematics (PPAM), September 6, 2015, doi: 10.1007/978-3-319-32149-3_12

Aydin Buluç, Scott Beamer, Kamesh Madduri, Krste Asanović, David Patterson., "Distributed-memory breadth-first search on massive graphs.", In D. Bader (editor), Parallel Graph Algorithms. CRC Press/Taylor-Francis, ( 2015)

Hongzhang Shan, Samuel Williams, Yili Zheng, Amir Kamil, Katherine Yelick,, "Implementing High-Performance Geometric Multigrid Solver with Naturally Grained Messages", 9th International Conference on Partitioned Global Address Space Programming Models (PGAS), September 2015, 38--46, doi: 10.1109/PGAS.2015.12

Mahantesh Halappanavar, Alex Pothen, Ariful Azad, Fredrik Manne, Johannes Langguth, Arif Khan, "Codesign Lessons Learned from Implementing Graph Matching on Multithreaded Architectures", IEEE Computer, August 2015,

Abhinav Sarje, Parallel Performance Optimizations on Unstructured Mesh-Based Simulations, International Conference on Computational Science, June 2015,

Abhinav Sarje, Sukhyun Song, Douglas Jacobsen, Kevin Huck, Jeffrey Hollingsworth, Allen Malony, Samuel Williams, and Leonid Oliker, "Parallel Performance Optimizations on Unstructured Mesh-Based Simulations", Procedia Computer Science, 1877-0509, June 2015, 51:2016-2025, doi: 10.1016/j.procs.2015.05.466

This paper addresses two key parallelization challenges the unstructured mesh-based ocean modeling code, MPAS-Ocean, which uses a mesh based on Voronoi tessellations: (1) load imbalance across processes, and (2) unstructured data access patterns, that inhibit intra- and inter-node performance. Our work analyzes the load imbalance due to naive partitioning of the mesh, and develops methods to generate mesh partitioning with better load balance and reduced communication. Furthermore, we present methods that minimize both inter- and intra- node data movement and maximize data reuse. Our techniques include predictive ordering of data elements for higher cache efficiency, as well as communication reduction approaches. We present detailed performance data when running on thousands of cores using the Cray XC30 supercomputer and show that our optimization strategies can exceed the original performance by over 2×. Additionally, many of these solutions can be broadly applied to a wide variety of unstructured grid-based computations.

Protonu Basu, Samuel Williams, Brian Van Straalen, Mary Hall, Leonid Oliker, Phillip Colella, "Compiler-Directed Transformation for Higher-Order Stencils", International Parallel and Distributed Processing Symposium (IPDPS), May 2015,

Evangelos Georganas, Aydin Buluç, Jarrod Chapman, Leonid Oliker, Daniel Rokhsar, Katherine Yelick, "MerAligner: A Fully Parallel Sequence Aligner", IEEE 29th International Parallel and Distributed Processing Symposium (IPDPS), May 2015, 561--570, doi: 10.1109/IPDPS.2015.96

Aligning a set of query sequences to a set of target sequences is an important task in bioinformatics. In this work we present merAligner, a highly parallel sequence aligner that implements a seed -- and -- extend algorithm and employs parallelism in all of its components. MerAligner relies on a high performance distributed hash table (seed index) and uses one-sided communication capabilities of the Unified Parallel C to facilitate a fine-grained parallelism. We leverage communication optimizations at the construction of the distributed hash table and software caching schemes to reduce communication during the aligning phase. Additionally, merAligner preprocesses the target sequences to extract properties enabling exact sequence matching with minimal communication. Finally, we efficiently parallelize the I/O intensive phases and implement an effective load balancing scheme. Results show that merAligner exhibits efficient scaling up to thousands of cores on a Cray XC30 supercomputer using real human and wheat genome data while significantly outperforming existing parallel alignment tools.

Ariful Azad, Aydin Buluc, John Gilbert, "Parallel Triangle Counting and Enumeration using Matrix Algebra", Workshop on Graph Algorithms Building Blocks (GABB), in conjunction with IPDPS, IEEE, May 2015,

Ariful Azad, Aydin Buluç, Alex Pothen, "A Parallel Tree Grafting Algorithm for Maximum Cardinality Matching in Bipartite Graphs", International Parallel and Distributed Processing Symposium (IPDPS), May 2015,

Hongzhang Shan, Samuel Williams, Wibe de Jong, Leonid Oliker, "Thread-Level Parallelization and Optimization of NWChem for the Intel MIC Architecture", Programming Models and Applications for Multicores and Manycores (PMAM), February 2015,

Costin Iancu, Nicholas Chaimov, Khaled Z. Ibrahim, Samuel Williams, "Exploiting Communication Concurrency on High Performance Computing Systems", Programming Models and Applications for Multicores and Manycores (PMAM), February 2015,

Aydin Buluç, Henning Meyerhenke, Ilya Safro, Peter Sanders, Christian Schulz., "Recent advances in graph partitioning", ArXiv, ( 2015)

Thorsten Kurth, Andrew Pochinsky, Abhinav Sarje, Sergey Syritsyn, Andre Walker-Loud, "High-Performance I/O: HDF5 for Lattice QCD", arXiv:1501.06992, January 2015,

Practitioners of lattice QCD/QFT have been some of the primary pioneer users of the state-of-the-art high-performance-computing systems, and contribute towards the stress tests of such new machines as soon as they become available. As with all aspects of high-performance-computing, I/O is becoming an increasingly specialized component of these systems. In order to take advantage of the latest available high-performance I/O infrastructure, to ensure reliability and backwards compatibility of data files, and to help unify the data structures used in lattice codes, we have incorporated parallel HDF5 I/O into the SciDAC supported USQCD software stack. Here we present the design and implementation of this I/O framework. Our HDF5 implementation outperforms optimized QIO at the 10-20% level and leaves room for further improvement by utilizing appropriate dataset chunking.

"Machine learning and understanding for intelligent extreme scale scientific computing and discovery", DOE ASCR Machine Learning Workshop Report, January 2015, doi: 10.2172/1471083

D Unat, C Chan, W Zhang, S Williams, J Bachan, J Bell, J Shalf, "ExaSAT: An exascale co-design tool for performance modeling", International Journal of High Performance Computing Applications, January 2015, 29:209--232, doi: 10.1177/1094342014568690

E Georganas, A Buluç, J Chapman, S Hofmeyr, C Aluru, R Egan, L Oliker, D Rokhsar, K Yelick, "HipMer: An extreme-scale de novo genome assembler", International Conference for High Performance Computing, Networking, Storage and Analysis, SC, January 1, 2015, 15-20-No, doi: 10.1145/2807591.2807664

2014

Khaled Z. Ibrahim, Samuel W. Williams, Evgeny Epifanovsky, Anna I. Krylov, "Analysis and Tuning of Libtensor Framework on Multicore Architectures", High Performance Computing Conference (HIPC), December 2014,

Samuel Williams, HPGMG-FV, FastForward2 Proxy App Presentation, December 2014,

Mark Adams, Samuel Williams, Jed Brown, HPGMG, Birds of a Feather (BoF), Supercomputing, November 2014,

Yu Jung Lo, Samuel Williams, Brian Van Straalen, Terry J. Ligocki, Matthew J. Cordery, Leonid Oliker, Mary W. Hall, "Roofline Model Toolkit: A Practical Tool for Architectural and Program Analysis", Performance Modeling, Benchmarking and Simulation of High Performance Computer Systems (PMBS), November 2014, doi: 10.1007/978-3-319-17248-4_7

Protonu Basu, Samuel Williams, Brian Van Straalen, Leonid Oliker, Mary Hall, "Converting Stencils to Accumulations for Communication-Avoiding Optimization in Geometric Multigrid", Workshop on Stencil Computations (WOSC), October 2014,

Hongzhang Shan, Amir Kamil, Samuel Williams, Yili Zheng, Katherine Yelick, "Evaluation of PGAS Communication Paradigms with Geometric Multigrid", Proceedings of the 8th International Conference on Partitioned Global Address Space Programming Models (PGAS), October 2014, doi: 10.1145/2676870.2676874

Partitioned Global Address Space (PGAS) languages and one-sided communication enable application developers to select the communication paradigm that balances the performance needs of applications with the productivity desires of programmers. In this paper, we evaluate three different one-sided communication paradigms in the context of geometric multigrid using the miniGMG benchmark. Although miniGMG's static, regular, and predictable communication does not exploit the ultimate potential of PGAS models, multigrid solvers appear in many contemporary applications and represent one of the most important communication patterns. We use UPC++, a PGAS extension of C++, as the vehicle for our evaluation, though our work is applicable to any of the existing PGAS languages and models. We compare performance with the highly tuned MPI baseline, and the results indicate that the most promising approach towards achieving performance and ease of programming is to use high-level abstractions, such as the multidimensional arrays provided by UPC++, that hide data aggregation and messaging in the runtime library.

Hongzhang Shan, Samuel Williams, Wibe de Jong, Leonid Oliker, "Thread-Level Parallelization and Optimization of NWChem for the Intel MIC Architecture", LBNL Technical Report, October 2014, LBNL 6806E,

Abhinav Sarje, Xiaoye S Li, Alexander Hexemer, "Tuning HipGISAXS on Multi and Many Core Supercomputers", High Performance Computing Systems. Performance Modeling, Benchmarking and Simulation, Denver, CO, Springer International Publishing, 2014, 8551:217-238, doi: 10.1007/978-3-319-10214-6_11

With the continual development of multi and many-core architectures, there is a constant need for architecture-specific tuning of application-codes in order to realize high computational performance and energy efficiency, closer to the theoretical peaks of these architectures. In this paper, we present optimization and tuning of HipGISAXS, a parallel X-ray scattering simulation code [9], on various massively-parallel state-of-the-art supercomputers based on multi and many-core processors. In particular, we target clusters of general-purpose multi-cores such as Intel Sandy Bridge and AMD Magny Cours, and many-core accelerators like Nvidia Kepler GPUs and Intel Xeon Phi coprocessors. We present both high-level algorithmic and low-level architecture-aware optimization and tuning methodologies on these platforms. We cover a detailed performance study of our codes on single and multiple nodes of several current top-ranking supercomputers. Additionally, we implement autotuning of many of the algorithmic and optimization parameters for dynamic selection of their optimal values to ensure high-performance and high-efficiency.

Abhinav Sarje, Xiaoye S Li, Alexander Hexemer, "High-Performance Inverse Modeling with Reverse Monte Carlo Simulations", 43rd International Conference on Parallel Processing, Minneapolis, MN, IEEE, September 2014, 201-210, doi: 10.1109/ICPP.2014.29

In the field of nanoparticle material science, X-ray scattering techniques are widely used for characterization of macromolecules and particle systems (ordered, partially-ordered or custom) based on their structural properties at the micro- and nano-scales. Numerous applications utilize these, including design and fabrication of energy-relevant nanodevices such as photovoltaic and energy storage devices. Due to its size, analysis of raw data obtained through present ultra-fast light beamlines and X-ray scattering detectors has been a primary bottleneck in such characterization processes. To address this hurdle, we are developing high-performance parallel algorithms and codes for analysis of X-ray scattering data for several of the scattering methods, such as the Small Angle X-ray Scattering (SAXS), which we talk about in this paper. As an inverse modeling problem, structural fitting of the raw data obtained through SAXS experiments is a method used for extracting meaningful information on the structural properties of materials. Such fitting processes involve a large number of variable parameters and, hence, require a large amount of computational power. In this paper, we focus on this problem and present a high-performance and scalable parallel solution based on the Reverse Monte Carlo simulation algorithm, on highly-parallel systems such as clusters of multicore CPUs and graphics processors. We have implemented and optimized our algorithm on generic multi-core CPUs as well as the Nvidia GPU architectures with C++ and CUDA. We also present detailed performance results and computational analysis of our code.

Adam Lugowski, Shoaib Kamil, Aydın Buluç, Samuel Williams, Erika Duriakova, Leonid Oliker, Armando Fox, John R. Gilbert,, "Parallel processing of filtered queries in attributed semantic graphs", Journal of Parallel and Distributed Computing (JPDC), September 2014, doi: 10.1016/j.jpdc.2014.08.010

Nan Ding, Weu Xue, Xu Ji, Haoyu Xu, Zhenya Song, "CESMTuner: An Auto-Tuning Framework for the Community Earth System Model", HPCC'14, IEEE, August 20, 2014, doi: 10.1109/HPCC.2014.51

George Michelogiannakis, Alexander Williams, Samuel Williams, John Shalf, "Collective Memory Transfers for Multi-Core Chips", International Conference on Supercomputing (ICS), June 2014, doi: 10.1145/2597652.2597654

H. M. Aktulga, A. Buluc, S. Williams, C. Yang, "Optimizing Sparse Matrix-Multiple Vector Multiplication for Nuclear Configuration Interaction Calculations", International Parallel and Distributed Processing Symposium (IPDPS 2014), May 2014, doi: 10.1109/IPDPS.2014.125

Mark F. Adams, Jed Brown, John Shalf, Brian Van Straalen, Erich Strohmaier, Samuel Williams, "HPGMG 1.0: A Benchmark for Ranking High Performance Computing Systems", LBNL Technical Report, 2014, LBNL 6630E,

Samuel Williams, Mike Lijewski, Ann Almgren, Brian Van Straalen, Erin Carson, Nicholas Knight, James Demmel, "s-step Krylov subspace methods as bottom solvers for geometric multigrid", Parallel and Distributed Processing Symposium, 2014 IEEE 28th International, January 2014, 1149--1158, doi: 10.1109/IPDPS.2014.119

2013

Protonu Basu, Anand Venkat, Mary Hall, Samuel Williams, Brian Van Straalen, Leonid Oliker, "Compiler generation and autotuning of communication-avoiding operators for geometric multigrid", 20th International Conference on High Performance Computing (HiPC), December 2013, 452--461,

Hongzhang Shan, Brian Austin, Wibe de Jong, Leonid Oliker, Nick Wright, Edoardo Apra, "Performance Tuning of Fock Matrix and Two Electron Integral Calculations for NWChem on Leading HPC Platforms", Performance Modeling, Benchmarking and Simulation of High Performance Computer Systems (PMBS), November 2013, doi: 10.1007/978-3-319-10214-6_13

Bei Wang, Stephane Ethier, William Tang, Timothy Williams, Khaled Z. Ibrahim, Kamesh Madduri, Samuel Williams, Leonid Oliker, "Kinetic Turbulence Simulations at Extreme Scale on Leadership-Class Systems", Proceedings of the International Conference on High Performance Computing, Networking, Storage and Analysis (SC), November 2013, doi: 10.1145/2503210.2503258

Slim T. Chourou, Abhinav Sarje, Xiaoye Li, Elaine Chan and Alexander Hexemer, "HipGISAXS: a high-performance computing code for simulating grazing-incidence X-ray scattering data", Journal of Applied Crystallography, 2013, 46:1781-1795, doi: 10.1107/ S0021889813025843

We have implemented a flexible Grazing Incidence Small-Angle Scattering (GISAXS) simulation code in the framework of the Distorted Wave Born Approximation (DWBA) that effectively utilizes the parallel processing power provided by graphics processors and multicore processors. This constitutes a handy tool for experimentalists facing a massive flux of data, allowing them to accurately simulate the GISAXS process and analyze the produced data. The software computes the diffraction image for any given superposition of custom shapes or morphologies in a user-defined region of the reciprocal space for all possible grazing incidence angles and sample orientations. This flexibility then allows to easily tackle a wide range of possible sample structures such as nanoparticles on top of or embedded in a substrate or a multilayered structure. In cases where the sample displays regions of significant refractive index contrast, an algorithm has been implemented to perform a slicing of the sample and compute the averaged refractive index profile to be used as the reference geometry of the unperturbed system. Preliminary tests show good agreement with experimental data for a variety of commonly encountered nanostrutures.

Samuel Williams, At Exascale, Will Bandwidth Be Free?, DOE ModSim Workshop, 2013,

Tim Mattson, David Bader, Jon Berry, Aydin Buluc, Jack Dongarra, Christos Faloutsos, John Feo, John Gilbert, Joseph Gonzalez, Bruce
Hendrickson, Jeremy Kepner, Charles Leiserson, Andrew Lumsdaine, David Padua, Stephen Poole, Steve Reinhardt, Mike Stonebraker, Steve Wallach,
Andrew Yoo, "Standards for Graph Algorithm Primitives", HPEC, 2013,

James Demmel, Samuel Williams, Katherine Yelick, "Automatic Performance Tuning (Autotuning)", The Berkeley Par Lab: Progress in the Parallel Computing Landscape, edited by David Patterson, Dennis Gannon, Michael Wrinn, (Microsoft Research: August 2013) Pages: 337-376

Khaled Z Ibrahim, Kamesh Madduri, Samuel Williams, Bei Wang, Stephane Ethier, Leonid Oliker, "Analysis and optimization of gyrokinetic toroidal simulations on homogeneous and heterogeneous platforms", International Journal of High Performance Computing Applications (IJHPCA), July 2013, doi: 10.1177/1094342013492446

P. Basu, A. Venkat, M. Hall, S. Williams, B. Van Straalen, L. Oliker, "Compiler Generation and Autotuning of Communication-Avoiding Operators for Geometric Multigrid", Workshop on Stencil Computations (WOSC), 2013,

Christopher D. Krieger, Michelle Mills Strout, Catherine Olschanowsky, Andrew Stone, Stephen Guzik, Xinfeng Gao, Carlo Bertolli, Paul H.J. Kelly, Gihan Mudalige, Brian Van Straalen, Sam Williams, "Loop chaining: A programming abstraction for balancing locality and parallelism", Parallel and Distributed Processing Symposium Workshops & PhD Forum (IPDPSW), 2013 IEEE 27th International, May 2013, 375--384, doi: 10.1109/IPDPSW.2013.68

Aydın Buluç, Erika Duriakova, Armando Fox, John Gilbert, Shoaib Kamil, Adam Lugowski, Leonid Oliker, Samuel Williams, "High-Productivity and High-Performance Analysis of Filtered Semantic Graphs", International Parallel and Distributed Processing Symposium (IPDPS), 2013, doi: 10.1145/2370816.2370897

Abhinav Sarje, Samuel Williams, David H. Bailey, "MPQC: Performance analysis and optimization", LBNL Technical Report, February 2013, LBNL 6076E,

2012

Samuel Williams, Dhiraj D. Kalamkar, Amik Singh, Anand M. Deshpande, Brian Van Straalen, Mikhail Smelyanskiy,
Ann Almgren, Pradeep Dubey, John Shalf, Leonid Oliker, "Implementation and Optimization of miniGMG - a Compact Geometric Multigrid Benchmark", December 2012, LBNL 6676E,

Samuel Williams, Optimization of Geometric Multigrid for Emerging Multi- and Manycore Processors, Supercomputing (SC), November 2012,

Abhinav Sarje, Xiaoye S. Li, Slim Chourou, Elaine R. Chan, Alexander Hexemer, "Massively Parallel X-ray Scattering Simulations", Supercomputing, November 2012,

Although present X-ray scattering techniques can provide tremendous information on the nano-structural properties of materials that are valuable in the design and fabrication of energy-relevant nano-devices, a primary challenge remains in the analyses of such data. In this paper we describe a high-performance, flexible, and scalable Grazing Incidence Small Angle X-ray Scattering simulation algorithm and codes that we have developed on multi-core/CPU and many-core/GPU clusters. We discuss in detail our implementation, optimization and performance on these platforms. Our results show speedups of ~125x on a Fermi-GPU and ~20x on a Cray-XE6 24-core node, compared to a sequential CPU code, with near linear scaling on multi-node clusters. To our knowledge, this is the first GISAXS simulation code that is flexible to compute scattered light intensities in all spatial directions allowing full reconstruction of GISAXS patterns for any complex structures and with high-resolutions while reducing simulation times from months to minutes.

S. Williams, D. Kalamkar, A. Singh, A. Deshpande, B. Van Straalen, M. Smelyanskiy, A. Almgren, P. Dubey, J. Shalf, L. Oliker, "Optimization of Geometric Multigrid for Emerging Multi- and Manycore Processors", Proceedings of the International Conference on High Performance Computing, Networking, Storage and Analysis (SC), November 2012, doi: 10.1109/SC.2012.85

B. Wang, S. Ethier, W. Tang, K. Ibrahim, K. Madduri, S. Williams, "Advances in gyrokinetic particle in cell simulation for fusion plasmas to Extreme scale", Supercomputing (SC), 2012,

Hongzhang Shan, Brian Austin, Nicholas Wright, Erich Strohmaier, John Shalf, Katherine Yelick, "Accelerating Applications at Scale Using One-Sided Communication", Santa Barbara, CA, The 6th Conference on Partitioned Global Address Programming Models, October 10, 2012,

A. Buluç, A. Fox, J. R. Gilbert, S. Kamil, A. Lugowski, L. Oliker, S. Williams, "High-performance analysis of filtered semantic graphs", PACT '12 Proceedings of the 21st international conference on Parallel architectures and compilation techniques (extended abstract), 2012, doi: 10.1145/2370816.2370897

J. Krueger, P. Micikevicius, S. Williams, "Optimization of Forward Wave Modeling on Contemporary HPC Architectures", LBNL Technical Report, 2012, LBNL 5751E,

Hongzhang Shan, Erich Strohmaier, James Amundson, Eric G. Stern, "Optimizing The Advanced Accelerator Simulation Framework Synergia Using OpenMP", IWOMP'12 Proceedings of the 8th International Conference on OpenMP, June 11, 2012,

Abhinav Sarje, Next-Generation Scientific Computing with Graphics Processors, Beijing Computational Science Research Center, February 2012,

K Madduri, J Su, S Williams, L Oliker, S Ethier, K Yelick, "Optimization of parallel particle-to-grid interpolation on leading multicore platforms", IEEE Transactions on Parallel and Distributed Systems, January 1, 2012, 23:1915--1922, doi: 10.1109/TPDS.2012.28

2011

S. Williams, et al., Extracting Ultra-Scale Lattice Boltzmann Performance via Hierarchical and Distributed Auto-Tuning, Supercomputing (SC), 2011,

S. Williams, et al., Stencil Computations on CPUs, Stanford Earth Sciences Algorithms and Architectures Initiative (SESAAI), 2011,

S. Williams, et al., Performance Optimization of HPC Applications on Multi- and Manycore Processors, Workshop on Hybrid Technologies for NASA Applications, 4th Internation Conference on Space Mission Challenges for Information Technology, 2011,

J. Demmel, K. Yelick, M. Anderson, G. Ballard, E. Carson, I. Dumitriu, L. Grigori, M. Hoemmen, O. Holtz, K. Keutzer, N. Knight, J. Langou, M. Mohiyuddin, O. Schwartz, E. Solomonik, S. Williams, Hua Xiang, Rethinking Algorithms for Future Architectures: Communication-Avoiding Algorithms, Hot Chips 23, 2011,

S. Williams, et al, Stencil Computations on CPUs, Society of Exploration Geophysicists High-Performance Computing Workshop (SEG), July 2011,

P. Narayanan, A. Koniges, L. Oliker, R. Preissl, S. Williams, N. Wright, M. Umansky, X. Xu, S. Ethier, W. Wang, J. Candy, J. Cary, "Performance Characterization for Fusion Co-design Applications", Cray Users Group (CUG), May 2011,

A. Kaiser, S. Williams, K. Madduri, K. Ibrahim, D. Bailey, J. Demmel, E. Strohmaier, "TORCH Computational Reference Kernels: A Testbed for Computer Science Research", LBNL Technical Report, 2011, LBNL 4172E,

Kamesh Madduri, Khaled Ibrahim, Samuel Williams, Eun-Jin Im, Stephane Ethier, John Shalf, Leonid Oliker, "Gyrokinetic toroidal simulations on leading multi- and manycore HPC systems", Proceedings of the International Conference on High Performance Computing, Networking, Storage and Analysis (SC), January 2011, 23, doi: 10.1145/2063384.2063415

Samuel Williams, Oliker, Carter, John Shalf, "Extracting ultra-scale Lattice Boltzmann performance via hierarchical and distributed auto-tuning", Proceedings of the International Conference on High Performance Computing, Networking, Storage and Analysis (SC), New York, NY, USA, ACM, January 2011, 55, doi: 10.1145/2063384.2063458

Jens Krueger, David Donofrio, John Shalf, Marghoob Mohiyuddin, Samuel Williams, Leonid Oliker, Franz-Josef Pfreund, "Hardware/software co-design for energy-efficient seismic modeling", Proceedings of the International Conference on High Performance Computing, Networking, Storage and Analysis (SC), January 2011, 73, doi: 10.1145/2063384.2063482

Kamesh Madduri, Eun-Jin Im, Khaled Z. Ibrahim, Samuel Williams, Stephane Ethier, Leonid Oliker, "Gyrokinetic Particle-in-cell Optimization on Emerging Multi- and Manycore Platforms", Parallel Computing (PARCO), January 2011, 37:501 - 520, doi: 10.1016/j.parco.2011.02.001

David H. Bailey, Robert F. Lucas, Samuel W. Williams, ed., Performance Tuning of Scientific Applications, (CRC Press: 2011)

M. Christen, N. Keen, T. Ligocki, L. Oliker, J. Shalf, B. van Straalen, S. Williams, "Automatic Thread-Level Parallelization in the Chombo AMR Library", LBNL Technical Report, 2011, LBNL 5109E,

David H. Bailey, Lin-Wang Wang, Hongzhang Shan, Zhengji Zhao, Juan Meza, Erich Strohmaier, Byounghak Lee, "Tuning an electronic structure code", Performance Tuning of Scientific Applications, edited by David H. Bailey, Robert F. Lucas, Samuel W. Williams, (CRC Press: 2011) Pages: 339-354 doi: 10.1201/b10509

2010

Khaled Z. Ibrahim, Erich Strohmaier, "Characterizing the Relation Between Apex-Map Synthetic Probes and Reuse Distance Distributions", The 39th International Conference on Parallel Processing (ICPP), 2010, 353 -362,

Samuel W. Williams, David H. Bailey, "Parallel Computer Architecture", Performance Tuning of Scientific Applications, edited by David H. Bailey, Robert F. Lucas, Samuel W. Williams, (CRC Press: 2010) Pages: 11-33

S. Williams, N. Bell, J. W. Choi, M. Garland, L. Oliker, R. Vuduc, "Sparse Matrix-Vector Multiplication on Multicore and Accelerators", chapter in Scientific Computing with Multicore and Accelerators, edited by Jack Dongarra, David A. Bader, Jakub Kurzak, ( 2010)

S. Williams, "The Roofline Model", chapter in Performance Tuning of Scientific Applications, edited by David H. Bailey, Robert F. Lucas, Samuel W. Williams, (CRC Press: 2010)

Hongzhang Shan, Erich Strohmaier, "Developing a Parameterized Performance Proxy for Sequential Scientific Kernels", 12th IEEE International Conference on High Performance Computing and Communications (HPCC), 2010, September 1, 2010, doi: 10.1109/HPCC.2010.50

A. Kaiser, S. Williams, K. Madduri, K. Ibrahim, D. Bailey, J. Demmel, E. Strohmaier, "A Principled Kernel Testbed for Hardware/Software Co-Design Research", Proceedings of the 2nd USENIX Workshop on Hot Topics in Parallelism (HotPar), 2010,

S. Williams, et al., Lattice Boltzmann Hybrid Auto-tuning on High-End Computational Platforms, Workshop on Programming Environments for Emerging Parallel Systems (PEEPS), 2010,

E. Strohmaier, S. Williams, A. Kaiser, K. Madduri, K. Ibrahim, D. Bailey, J. Demmel,, "A Kernel Testbed for Parallel Architecture, Language, and Performance Research", International Conference of Numerical Analysis and Applied Mathematics (ICNAAM), June 1, 2010, doi: 10.1063/1.3497950

A. Kaiser, S. Williams, K. Madduri, K. Ibrahim, D. Bailey, J. Demmel, E. Strohmaier, "A Principled Kernel Testbed for Hardware/Software Co-Design Research", Proceedings of the 2nd USENIX Workshop on Hot Topics in Parallelism (HotPar), 2010,

K Datta, S Williams, V Volkov, J Carter, L Oliker, J Shalf, K Yelick, "Auto-tuning stencil computations on multicore and accelerators", Scientific Computing with Multicore and Accelerators, ( 2010) Pages: 219--254 doi: 10.1201/b10376

Shoaib Kamil, Cy Chan, Leonid Oliker, John Shalf, Samuel Williams, "An auto-tuning framework for parallel multicore stencil computations", International Parallel & Distributed Processing Symposium (IPDPS), January 1, 2010, 1-12, doi: 10.1109/IPDPS.2010.5470421

S Williams, K Datta, L Oliker, J Carter, J Shalf, K Yelick, "Auto-Tuning Memory-Intensive Kernels for Multicore", Chapman \& Hall/CRC Computational Science, (CRC Press: 2010) Pages: 273--296 doi: 10.1201/b10509-14

A. Chandramowlishwaran, S. Williams, L. Oliker, I. Lashuk, G. Biros, R. Vuduc, "Optimizing and Tuning the Fast Multipole Method for State-of-the-Art Multicore Architectures", International Parallel & Distributed Processing Symposium (IPDPS), 2010, doi: 10.1109/IPDPS.2010.5470415

2009

"Accelerating Time-to-Solution for Computational Science and Engineering", J. Demmel, J. Dongarra, A. Fox, S. Williams, V. Volkov, K. Yelick, SciDAC Review, Number 15, December 2009,

S. Zhou, D. Duffy, T. Clune, M. Suarez, S. Williams, M. Halem, "The Impact of IBM Cell Technology on the Programming Paradigm in the Context of Computer Systems for Climate and Weather Models", Concurrency and Computation:Practice and Experience (CCPE), August 2009, doi: 10.1002/cpe.1482

Zhengji Zhao, Juan Meza, Byounghak Lee, Hongzhang Shan, Eric Strohmaier, David H. Bailey, Lin-Wang Wang, "The linearly scaling 3D fragment method for large scale electronic structure calculations", Journal of Physics: Conference Series, July 1, 2009,

Shoaib Kamil, Cy Chan, Samuel Williams, Leonid Oliker, John Shalf, Mark Howison, E. Wes Bethel, Prabhat, "A Generalized Framework for Auto-tuning Stencil Computations", BEST PAPER AWARD - Cray User Group Conference (CUG), Atlanta, GA, May 4, 2009, LBNL 2078E,

Best Paper Award

S. Williams, J. Carter, L. Oliker, J. Shalf, K. Yelick, "Resource-Efficient, Hierarchical Auto-Tuning of a Hybrid Lattice Boltzmann Computation on the Cray XT4", Proceedings of the Cray User Group (CUG), Atlanta, GA, 2009,

S. Williams, et al., A Generalized Framework for Auto-tuning Stencil Computations, Cray User Group (CUG), 2009,

S. Williams, et al., Resource-Efficient, Hierarchical Auto-Tuning of a Hybrid Lattice Boltzmann Computation on the Cray XT4, Cray User Group (CUG), 2009,

S. Williams, A. Waterman, D. Patterson, "Roofline: an insightful visual performance model for multicore architectures", Communications of the ACM (CACM), April 2009, doi: 10.1145/1498765.1498785

K Madduri, S Williams, S Ethier, L Oliker, J Shalf, E Strohmaier, K Yelick, "Memory-efficient optimization of gyrokinetic particle-to-grid interpolation for multicore processors", Proceedings of the Conference on High Performance Computing Networking, Storage and Analysis, SC 09, January 2009, doi: 10.1145/1654059.1654108

Marghoob Mohiyuddin, Murphy, Oliker, Shalf, Wawrzynek, Samuel Williams, "A design methodology for domain-optimized power-efficient supercomputing", Proceedings of the International Conference on High Performance Computing, Networking, Storage and Analysis (SC), 2009, doi: 10.1145/1654059.1654072

J Gebis, L Oliker, J Shalf, S Williams, K Yelick, "Improving memory subsystem performance using ViVA: Virtual vector architecture", Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2009, 5455 LNC:146--158, doi: 10.1007/978-3-642-00454-4_16

K. Datta, S. Williams, V. Volkov, J. Carter, L. Oliker, J. Shalf, K. Yelick, "Auto-Tuning the 27-point Stencil for Multicore", Proceedings of Fourth International Workshop on Automatic Performance Tuning (iWAPT2009), January 2009,

K Datta, S Kamill, S Williams, L Oliker, J Shalf, K Yelick, "Optimization and performance modeling of stencil computations on modern microprocessors", SIAM Review, 2009, 51:129--159, doi: 10.1137/070693199

S Williams, J Carter, L Oliker, J Shalf, K Yelick, "Optimization of a lattice Boltzmann computation on state-of-the-art multicore platforms", Journal of Parallel and Distributed Computing, 2009, 69:762--777, doi: 10.1016/j.jpdc.2009.04.002

Kamesh Madduri, Williams, Ethier, Oliker, Shalf, Strohmaier, Katherine A. Yelick, Memory-efficient optimization of Gyrokinetic particle-to-grid interpolation for multicore processors, Proceedings of the International Conference on High Performance Computing, Networking, Storage and Analysis (SC), 2009,

2008

S. Williams, Auto-tuning Performance on Multicore Computers, Ph.D. Thesis Dissertation Talk, University of California at Berkeley, 2008,

Lin-Wang Wang, Byounghak Lee, Hongzhang Shan, Zhengji Zhao, Juan Meza, Erich Strohmaier, David H. Bailey, "Linearly scaling 3D fragment method for large-scale electronic structure calculations", Proceedings of SC08, November 2008,

Samuel Webb Williams, Andrew Waterman, David A. Patterson, "Roofline: An Insightful Visual Performance Model for Floating-Point Programs and Multicore Architectures", EECS Tech Report UCB/EECS-2008-134, October 2008,

S. Williams, et al, "Auto-tuning and the Roofline model", View From the Top: Craig Mundie (Ph.D student poster session), 2008,

S. Williams, et al., The Roofline Model: A Pedagogical Tool for Auto-tuning Kernels on Multicore Architectures, Hot Chips 20, August 10, 2008,

S. Williams, et al., A Vision for Integrating Performance Counters into the Roofline model, UPCRC PMU Workshop (Performance Counters), 2008,

D. Bailey, J. Chame, C. Chen, J. Dongarra, M. Hall, J. Hollingsworth, P. Hovland, S. Moore, K. Seymour, J. Shin, A. Tiwari, S. Williams, H. You, "PERI Auto-tuning", SciDAC PI Meeting, Journal of Physics: Conference Series, 125 012001, 2008,

S. Williams, K. Datta, J. Carter, L. Oliker, J. Shalf, K. Yelick, D. Bailey, "PERI: Auto-tuning Memory Intensive Kernels for Multicore", SciDAC PI Meeting, Journal of Physics: Conference Series, 125 012038, July 2008, doi: 10.1088/1742-6596/125/1/012038

S. Williams, J. Carter, J. Demmel, L. Oliker, D. Patterson, J. Shalf, K. Yelick, R. Vuduc, "Autotuning Scientific Kernels on Multicore Systems", ASCR PI Meeting, 2008,

S. Williams, et al., PERI: Auto-tuning Memory Intensive Kernels for Multicore, SciDAC PI Meeting, 2008,

K. Datta, S. Williams, V. Volkov, M. Murphy, "Autotuning Structured Grid Kernels", ParLab Summer Retreat, 2008,

S. Zhou, D. Duffy, T. Clune, M. Suarez, S. Williams, M. Halem, "Impacts of the IBM Cell Processor on Supporting Climate Models", International Supercomputing Conference (ISC), 2008,

S. Williams, et. al, "The Roofline Model: A Pedagogical Tool for Program Analysis and Optimization", Parlab Summer Retreat, 2008,

K Datta, M Murphy, V Volkov, S Williams, J Carter, L Oliker, D Patterson, J Shalf, K Yelick, "Stencil computation optimization and auto-tuning on state-of-the-art multicore architectures", 2008 SC - International Conference for High Performance Computing, Networking, Storage and Analysis, SC 2008, January 2008, doi: 10.1109/SC.2008.5222004

S Williams, J Carter, L Oliker, J Shalf, K Yelick, "Lattice Boltzmann simulation optimization on leading multicore platforms", IPDPS Miami 2008 - Proceedings of the 22nd IEEE International Parallel and Distributed Processing Symposium, Program and CD-ROM, 2008, doi: 10.1109/IPDPS.2008.4536295

S. Williams, J. Carter, L. Oliker, J. Shalf, K. Yelick, Lattice Boltzmann simulation optimization on leading multicore platforms, IEEE International Symposium on Parallel & Distributed Processing (IPDPS)., Pages: 1-14 2008,

K. Datta, S. Williams, S. Kamil, "Autotuning Structured Grid Kernels", Parlab Winter Retreat, 2008,

S. Williams, et al., Autotuning Sparse and Structured Grid Kernels, Parlab Winter Retreat, 2008,

S. Williams, K. Datta, J. Carter, L. Oliker, J. Shalf, K. Yelick, D. Bailey, PERI -- Auto-tuning Memory-intensive Kernels for Multicore, Journal of Physics: Conference Series, Pages: 012038 2008,

Shoaib Kamil, Shalf, Erich Strohmaier, "Power efficiency in high performance computing", IPDPS, 2008, 1-8,

2007

S. Williams, et al., Optimization of Sparse Matrix-Vector Multiplication on Emerging Multicore Platforms, DOE/DOD Workshop on Emerging High-Performance Architectures and Applications, 2007,

Samuel Williams, Leonid Oliker, Richard Vuduc, John Shalf, Katherine Yelick, James Demmel, "Optimization of Sparse Matrix-Vector Multiplication on Emerging Multicore Platforms", Proceedings of the International Conference on High Performance Computing, Networking, Storage and Analysis (SC), November 2007, doi: 10.1145/1362622.1362674

S. Williams, et al., Optimization of Sparse Matrix-Vector Multiplication on Emerging Multicore Platforms, Supercomputing (SC), 2007,

S. Williams, et al., Tuning Sparse Matrix Vector Multiplication for multi-core processors, Center for Scalable Application Development Software (CScADS), 2007,

S. Williams, et al., Tuning Sparse Matrix Vector Multiplication for multi-core SMPs, Parlab Seminar, 2007,

Costin Iancu, Erich Strohmaier, "Optimizing communication overlap for high-speed networks", Principles and Practice of Parallel Programming (PPoPP), 2007,

Leonid Oliker, Julian Borrill, Hongzhang Shan, John Shalf, Investigation Of Leading HPC I/O Performance Using A Scientific-Application Derived Benchmark., 2007,

J. Shalf, L. Oliker, M. Lijewski, S. Kamil, J. Carter, A. Canning, S. Ethier, "Performance Characteristics of Potential Petascale Scientific Applications", Chapman & Hall/CRC Computational Science, (CRC Press: 2007) Pages: 1

Book Chapter

J. Carter, L. Oliker, J. Shalf, "Performance Evaluation of Scientific Applications on Modern Parallel Vector Systems", Extended Version: Lecture Notes in Computer Science, 2007,

S Williams, L Oliker, R Vuduc, J Shalf, K Yelick, J Demmel, "Optimization of sparse matrix-vector multiplication on emerging multicore platforms", Proceedings of the 2007 ACM/IEEE Conference on Supercomputing, SC 07, 2007, doi: 10.1145/1362622.1362674

S Williams, J Shalf, L Oliker, S Kamil, P Husbands, K Yelick, "Scientific computing kernels on the cell processor", International Journal of Parallel Programming, January 2007, 35:263--298, doi: 10.1007/s10766-007-0034-5

L. Oliker, A. Canning, J. Carter, C. Iancu, M. Lijewski, S. Kamil, J. Shalf, H. Shan, E. Strohmaier, S. Ethier, T. Goodale, "Scientific application performance on candidate petascale platforms", Proceedings - 21st International Parallel and Distributed Processing Symposium, IPDPS 2007; Abstracts and CD-ROM, 2007, doi: 10.1109/IPDPS.2007.370259

J. Carter, Y. He, J. Shalf, H. Shan, E. Strohmaier, H. Wasserman, "The Performance Effect of Multi-core on Scientific Applications", Proceedings of Cray User Group, 2007, LBNL 62662,

J. Levesque, J. Larkin, M. Foster, J. Glenski, G. Geissler, S. Whalen, B. Waldecker, J. Carter, D. Skinner, Y. He, H. Wasserman, J. Shalf, H. Shan, E. Strohmaier, "Understanding and Mitigating Multicore Performance Issues on the AMD Opteron Architecture", 2007, LBNL 62500,

John Shalf, Shoaib Kamil, David Bailey, Erich Strohmaier, Power Efficiency and the Top500, 2007,

L. Oliker, A. Canning, J. Carter, C. Iancu, M. Lijewski, S. Kamil, J. Shalf, H. Shan, E. Strohmaier, S. Ethier, T. Goodale, "Performance Characteristics of Potential Petascale Scientific Applications", Petascale Computing: Algorithms and Applications. Chapman & Hall/CRC Computational Science Series (Hardcover), edited by David A. Bader, ( 2007)

Chapter

2006

K. Asanovic, R. Bodik, B. Catanzaro, J. Gebis, P. Husbands, K. Keutzer, D. Patterson, W. Plishker, J. Shalf, S. Williams, K. Yelick, "The Landscape of Parallel Computing Research: A View from Berkeley", EECS Technical Report, December 2006,

S. Williams, et al., 3D Lattice Boltzmann Magneto-hydrodynamics (LBMHD3D), UTK Summit on Software and Algorithms for the Cell Processor, 2006,

S. Williams, J. Shalf, L. Oliker, P. Husbands, S. Kamil, K. Yelick, "The Potential of the Cell Processor for Scientific Computing", ACM International Conference on Computing Frontiers, 2006, doi: 10.1145/1128022.1128027

S. Williams, et al., The Potential of the Cell Processor for Scientific Computing, LBL Scientific Computing Seminar, 2006,

J. Carter, L. Oliker, J. Shalf, "Performance Evaluation of Scientific Applications on Modern Parallel Vector Systems", High Performance Computing for Computational Science., 2006,

Highest Ranked Conference Paper

J. Carter, L. Oliker, J. Shalf, "Performance Evaluation of Scientific Applications on Modern Parallel Vector Systems", VECPAR, 2006,

Jonathan Carter, Oliker, John Shalf, "Performance Evaluation of Scientific Applications on Modern Parallel Vector Systems", VECPAR, Springer Berlin/Heidelberg, 2006, 4395:490-503,

S Williams, J Shalf, L Oliker, S Kamil, P Husbands, K Yelick, The potential of the cell processor for scientific computing, Proceedings of the 3rd Conference on Computing Frontiers 2006, CF 06, Pages: 9--20 2006, doi: 10.1145/1128022.1128027

S Kamil, K Datta, S Williams, L Oliker, J Shalf, K Yelick, "Implicit and explicit optimizations for stencil computations", Proceedings of the 2006 ACM SIGPLAN Workshop on Memory Systems Performance and Correctness, MSPC 2006, 2006, 51--60, doi: 10.1145/1178597.1178605

Samuel Williams, Shalf, Oliker, Kamil, Husbands, Katherine A. Yelick, The potential of the cell processor for scientific computing, Conf. Computing Frontiers, Pages: 9-20 2006,

H Shan, E Strohmaier, J Qiang, DH Bailey, K Yelick, "Performance modeling and optimization of a high energy colliding beam simulation code", Proceedings of the 2006 ACM/IEEE Conference on Supercomputing, SC 06, January 2006, doi: 10.1145/1188455.1188557

2005

S. Williams, J. Shalf, L. Oliker, P. Husbands, K. Yelick, "Dense and Sparse Matrix Operations on the Cell Processor", LBNL Technical Report, 2005,

2004

E. Strohmaier, Hongzhang Shan, "Architecture Independent Performance Characterization and Benchmarking for Scientific Applications", International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems, Volendam, The Netherlands, October 2004,

Hongzhang Shan, E. Strohmaier, "Performance Characterization of Cray X1 and Their Implications for Application Performance Tuning", International Conference of Supercomputing, Malo, France, June 2004,

H. Shan, E. Strohmaier, L. Oliker, "Optimizing Performance of Superscalar Codes for a Single Cray X1 MSP", Proceedings of the 46th Cray User Group Conference:CUG, 2004,

2002

E. Strohmaier, Performance Characterization and Benchmarking for High Performance Systems and Applications, University of Tennessee, CS Seminar, November 8, 2002,

Erich Strohmaier, Performance Characterization and Benchmarking for High Performance Systems and Applications, CCS Seminar, October 9, 2002,

Erich Strohmaier, Benchmarking for High Performance Systems and Applications, DARPA HPCS Performance Workshop, September 19, 2002,

2001

C. Kozyrakis, D. Judd, J. Gebis, S. Williams, D. Patterson, K. Yelick, "Hardware/Compiler Co-development for an Embedded Media Processor", Proceedings of the IEEE, 2001, doi: 10.1109/5.964446

2000

C. Kozyrakis, J. Gebis, D. Martin, S. Williams, I. Mavroidis, S. Pope, D. Jones, D. Patterson, K. Yelick, Vector IRAM: A media-oriented vector processor with embedded DRAM, Hot Chips 12, 2000,

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