Narasimha R. Adiga IBM Engineering and Technology Services, Golden Enclave, Airport Road, Bangalore 560 017, India (anarasim@in.ibm.com). Mr. Adiga is a Staff Research and Development Engineer. In 1998 he received a B.E. degree from Karnataka Regional Engineering College, India. He subsequently joined IBM, where he has worked on the development of the PCI-PCIX exerciser/analyzer card and verification of the torus with a single-node BG/L compute chip for Blue Gene/L. Mr. Adiga is currently working on memory interface controller designs for future systems.

Matthias A. Blumrich IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (blumrich@us.ibm.com). Dr. Blumrich is a Research Staff Member in the Server Technology Department. 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. In 1998 he joined the IBM Research Division, where he has worked on scalable networking for servers and the Blue Gene supercomputing project. Dr. Blumrich is an author or coauthor of two patents and 12 technical papers.

Dong Chen IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (chendong@us.ibm.com). Dr. Chen is a Research Staff Member in the Exploratory Server Systems Department. 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 in 1991, 1992, and 1996, respectively. He continued as a postdoctoral researcher at the Massachusetts Institute of Technology from 1996 to 1998. In 1999 he joined the IBM Server Group, where he worked on optimizing applications for IBM RS/6000* SP systems. In 2000 he moved to the IBM Thomas J. Watson Research Center, where he has been working on many areas of the Blue Gene/L supercomputer and collaborating on the QCDOC project. Dr. Chen is an author or coauthor of more than 30 technical journal papers.

Paul Coteus IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (coteus@us.ibm.com). Dr. Coteus received his Ph.D. degree in physics from Columbia University in 1981. He continued working at Columbia to design an electron–proton collider, and from 1982 to 1988 was an Assistant Professor of Physics at the University of Colorado at Boulder, studying neutron production of charmed baryons. In 1988, he joined the IBM Thomas J. Watson Research Center as a Research Staff Member. Since 1994 he has managed the Systems Packaging Group, where he directs and designs advanced packaging and tools for high-speed electronics, including I/O circuits, memory system design and standardization of high-speed DRAM, and high-performance system packaging. His most recent work is in the system design and packaging of the Blue Gene/L supercomputer, where he served as packaging leader and program development manager. Dr. Coteus has coauthored numerous papers in the field of electronic packaging and holds 38 U.S. patents.

Alan Gara IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (alangara@us.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 Award for the QCDSP supercomputer in the most cost-effective category. He is the chief architect of the Blue Gene/L supercomputer. Dr. Gara also led the design and verification of the Blue Gene/L compute ASIC as well as the bring-up of the Blue Gene/L prototype system.

Mark E. Giampapa IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (giampapa@us.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 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 (philiph@us.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. 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, and the program chairman of the 1989 Winter Simulation Conference. Dr. Heidelberger is currently the vice president of ACM SIGMETRICS; he is a Fellow of the ACM and the IEEE.

Sarabjeet Singh IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (sarabj@us.ibm.com). Mr. Singh is a Senior Research and Development Engineer with the Engineering and Technology Services Division of IBM, currently on assignment at the IBM Thomas J. Watson Research Center. He received a B.Tech. degree in electrical engineering from the Indian Institute of Technology in 1996 and subsequently joined IBM, where he has worked on various research projects involving all aspects of ASIC and system-on-a-chip (SoC) design. Over the past seven years he has worked on many CMOS technologies (Blue Gene/L in Cu-11 technology), up to 700-MHz clock designs, asynchronous logic design, and Small Computer System Interface (SCSI) drive controllers to HPC systems. Mr. Singh is currently working on memory subsystem microarchitecture for an HPC system based on the STI cell.

Burkhard D. Steinmacher-Burow IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (steinmac@us.ibm.com). Dr. Steinmacher-Burow is a Research Staff Member in the Exploratory Server Systems Department. He received a B.S. degree in physics from the University of Waterloo in 1988, and M.S. and Ph.D. degrees from the University of Toronto in 1990 and 1994, respectively. He subsequently joined the Universitaet Hamburg and then the Deutsches Elektronen-Synchrotron to work in experimental particle physics. In 2001, he joined IBM at the Thomas J. Watson Research Center and has since worked in many hardware and software areas of the Blue Gene research program. Dr. Steinmacher-Burow is an author or coauthor of more than 80 technical papers.

Todd Takken IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (taken@us.ibm.com). Dr. Takken is a Research Staff Member at the IBM Thomas J. Watson Research Center. He received a B.A. degree from the University of Virginia and an M.A. degree from Middlebury College; he finished his Ph.D. degree in electrical engineering at Stanford University in 1997. He then joined the IBM Research Division, where he has worked in the areas of signal integrity analysis, decoupling and power system design, microelectronic packaging, parallel system architecture, packet routing, and network design. Dr. Takken holds more than a dozen U.S. patents.

Michael Tsao IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (mtsao@us.ibm.com). Dr. Tsao is a Research Staff Member at the IBM Thomas J. Watson Research Center. He received B.S.E.E, M.S.E.C.E, and Ph.D. degrees from the Electrical and Computer Engineering Department of the Carnegie-Mellon University in 1977, 1979, and 1983, respectively. He joined IBM at the Thomas J. Watson Research Center in 1983 and has worked on various multiprocessor projects including RP3, GF11, Vulcan, SP1, SP2, MXT, and BG/L. Dr. Tsao is currently working on cache chips for future processors.

Pavlos Vranas IBM Research Division, Thomas J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (vranasp@us.ibm.com). Dr. Vranas is a Research Staff Member in the Deep Computing Systems Department at the IBM Thomas J. Watson Research Center. He received his B.S. degree in physics from the University of Athens in 1985, and his M.S. and Ph.D. degrees in theoretical physics from the University of California at Davis in 1987 and 1990, respectively. He continued research in theoretical physics as a postdoctoral researcher at the Supercomputer Computations Research Institute, Florida State University (1990–1994), at Columbia University (1994–1998), and at the University of Illinois at Urbana–Champaign (1998–2000). In 2000 he joined IBM at the Thomas J. Watson Research Center, where he has worked on the architecture, design, verification, and bring-up of the Blue Gene/L supercomputer and is continuing his research in theoretical physics. Dr. Vranas is an author or coauthor of 59 papers in supercomputing and theoretical physics.

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