Pavlos Vranas Lawrence Livermore National Laboratory, Livermore, California 94550 (vranas1llnl.gov). Dr. Vranas received his B.S. degree in physics from the University of Athens, Greece, in 1985 and his Ph.D. degree in theoretical elementary particle physics from the University of California at Davis in 1990. He continued his research in theoretical physics as a postdoctoral researcher at the Supercomputing Computations Research Institute at Columbia University and at the University of Illinois at Urbana-Champaign. From 2000 to 2007, Dr. Vranas worked at the IBM Thomas J. Watson Research Center as a Research Staff Member with the core hardware architecture, design, and development team of the Blue Gene series of supercomputers while continuing his research in theoretical physics. Dr. Vranas performed the first numerical simulations using domain wall fermions and has played a key role in their application to quantum chromodynamics (QCD) and related theories. He received the Gordon Bell Prize in 1998 for his work on the Columbia University QCDSP supercomputer. In 2006, he received the 2006 Gordon Bell Prize for Special Achievement for simulations of QCD on the Blue Gene/L system, and in 2007 he received the IBM Outstanding Invention Achievement Award. Dr. Vranas has authored more than 70 papers in theoretical physics and supercomputing as well as 18 patents.

Matthias A. Blumrich IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (blumrichus.ibm.com). Dr. Blumrich is a Research Staff Member in the Blue Gene Systems Development group at the IBM Thomas J. Watson Research Center. He received a B.E.E. degree from the State University of New York at Stony Brook in 1986, and M.A. and Ph.D. degrees in computer science from Princeton University in 1991 and 1996, respectively. He joined IBM Research in 1998, where he has worked on scalable networking and memory systems for servers and the Blue Gene supercomputers. Dr. Blumrich is an author and coauthor of many patents and technical papers.

Dong Chen IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (chendongus.ibm.com). Dr. Chen is a Research Staff Member in the Deep Computing Systems Department of IBM. He received his B.S. degree in physics from Peking University in 1990, and M.A., M.Phil., and Ph.D. degrees in theoretical physics from Columbia University. He continued as a postdoctoral researcher at Massachusetts Institute of Technology before joining the IBM Server Group in 1999. He has been working in many areas related to the Blue Gene systems since 2000. Dr. Chen is an author or coauthor of more than 30 technical journal papers. He has received an IBM Outstanding Technical Achievement Award and five IBM Invention Achievement Awards. He also received two Gordon Bell Prizes for his contributions to QCDSP and Blue Gene/L supercomputers.

Alan Gara IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (alangaraus.ibm.com). Dr. Gara is a Research Staff Member at the IBM Thomas J. Watson Research Center. He received his Ph.D. degree in physics from the University of Wisconsin at Madison in 1986. In 1998 Dr. Gara received the Gordon Bell Prize in the most cost-effective category for the QCDSP supercomputer, and in 2006 he received the Gordon Bell Prize for Special Achievement. He is the Chief Architect of the Blue Gene line of supercomputers. In 2006, he was named a member of the IBM Academy and an IBM Fellow.

Mark E. Giampapa IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (giampapaus.ibm.com). Mr. Giampapa is a Senior Engineer in the Exploratory Server Systems Department. He received a B.A. degree in computer science from Columbia University. He joined the IBM Research Division in 1984 to work in the areas of parallel and distributed processing, and he has focused his research on distributed memory and shared memory parallel architectures and operating systems. Mr. Giampapa has received three IBM Outstanding Technical Achievement Awards for his work in distributed processing, simulation, and parallel operating systems. He holds 15 patents, with several more pending, and has published ten papers.

Philip Heidelberger IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (philiphus.ibm.com). Dr. Heidelberger received a B.A. degree in mathematics from Oberlin College in 1974 and a Ph.D. degree in operations research from Stanford University in 1978. He has been a Research Staff Member at the IBM Thomas J. Watson Research Center since 1978. His research interests include modeling and analysis of computer performance, probabilistic aspects of discrete event simulations, parallel simulation, and parallel computer architectures. He has authored more than 100 papers in these areas. He has been working on the Blue Gene Project since 2000. Dr. Heidelberger has served as Editor-in-Chief of the ACM Transactions on Modeling and Computer Simulation. He was the general chairman of the ACM Special Interest Group on Measurement and Evaluation (SIGMETRICS) Performance 2001 Conference, the program co-chairman of the ACM SIGMETRICS Performance 1992 Conference, the program chairman of the 1989 Winter Simulation Conference, and he was the vice president of ACM SIGMETRICS. He is a Fellow of the ACM and the IEEE.

Valentina Salapura IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (salapuraus.ibm.com). Dr. Salapura has been a technical leader for the Blue Gene program since its inception. She has contributed to the architecture and implementation of several generations of Blue Gene systems focusing on multithreaded, multicore architecture design and evaluation, and multiprocessor memory subsystems, interconnect, and synchronization. Most recently, she has been Unit Lead for several units of the Blue Gene/P* system, as well as a leader of the chip and system bring-up effort. She is currently working on power/performance characterization of the Blue Gene/P system and on the architecture of future IBM systems. Before joining IBM, Dr. Salapura was Assistant Professor with Technische Universität Wien. She received her Ph.D. degree from Technische Universität Wien, Vienna, Austria, and M.S. degrees in electrical engineering and computer science from University of Zagreb, Croatia. She is the recipient of the 2006 Gordon Bell Prize for Special Achievement for the Blue Gene/L supercomputer and quantum chromodynamics. She is the author of more than 60 papers on processor architecture and high-performance computing, and she holds many patents in this area. She was general co-chair of the 2006 ACM Computing Frontiers conference and program co-chair for the System Architecture and Applications track of the IEEE International Conference on Computer Design in 2006 and 2007. Dr. Salapura is a senior member of the IEEE.

James C. Sexton IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (sextonjcus.ibm.com). Dr. Sexton is a Research Staff Member at the IBM Thomas J. Watson Research Center. He received his Ph.D. degree in theoretical physics from Columbia University and has held research positions at the Fermi National Accelerator Laboratory (Fermilab), the Institute of Advanced Studies at Princeton University, and Trinity College, Dublin.

Ron Soltz Physics and Advanced Technologies Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (soltzllnl.gov). Dr. Soltz is a Staff Physicist at Lawrence Livermore National Laboratory (LLNL). He received his Ph.D. degree in physics from the Massachusetts Institute of Technology in Cambridge, Massachusetts, in 1994. He currently leads the LLNL research program for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. His interest in understanding nuclear matter at very highest temperatures and densities led him to begin calculations in lattice quantum chromodynamics, and this work led to the Gordon Bell Prize for Special Achievement in 2006.

Gyan Bhanot Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey 08855 (gyanbhanotgmail.com). Professor Bhanot received his Ph.D. degree in theoretical physics from Cornell University in 1979. He was a Research Staff Member at the IBM Research Division in the Physics Department from 1994 to 2001 and in the Computational Biology Group from 2001 to 2006. He worked on BG/L applications at IBM from 2003 to 2005. He is currently Professor of Biomedical Engineering at Rutgers University with joint appointments at the Cancer Institute of New Jersey and the BioMaPS Institute. His current research interest is in developing models for the initiation, progression, and metastasis of cancer and understanding complex disease phenotypes.

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