What’s a Supercomputer Good for Anyway?

What’s a Supercomputer Good for Anyway? Ruth Poole – IBM Software Engineer Blue Gene Control System

Overview • Applications • Current Customers • Future Directions • Architecture Foundations • Hardware Comparisons • Trends

Application Categories – Current Customers • Government and University • Nuclear stockpile stewardship • Other research • Computational Fluid Dynamics – CFD • Aerodynamics – aerospace, automotive, engine design • Weather/climate modeling • Physics / Astronomy • QCD – Quantum Chromodynamics • Flash – simulate supernovae explosions • LOFAR – radio telescope consisting of many small receivers • Biomedical • Computational chemistry • Drug discovery • DNA sequencing and search • Others • Finance • Oil / Gas exploration

NAMD - NAnoscale Molecular Dynamics • Theoretical and Computational Biophysics Group (TCB) and Parallel Programming Laboratory (PPL) at the University of Illinois at Urbana-Champaign • Simulate systems of millions of atoms • Use to build models of cellular processes • Current goal: model one micro-second of cell behavior

Blue Brain - EPFL • EPFL-IBM joint research project to create a cellular level, software replica of the Neocortical Column • Phase 1, rat brain with 10,000 neuron Neocortical Column with automatically generated, biologically accurate neurons completed November 26, 2007 • Study its function and dysfunction and to lay the foundation for large scale modeling of the mammalian brain

Materials Science • Blue Waters IBM / NSF collaboration project for open research • University of Illinois at Urbana-Champaign planned for 2011 • Design a substance from atoms that meets specific parameters for conductivity and strength

Robot Surgeons • Laser prostate surgery on a dog • Real-time data from MRI used to guide laser • Computer in Austin, Dog in Houston • TACC Lonestar, #38 on Top500.org

Simulated Plants • Computer model that mimics the process of evolution. • First model to simulate every step of the photosynthetic process. • Researchers have built a better plant, one that produces more leaves and fruit without needing extra fertilizer. • University of Illinois; Photo by Don Hamerman

Background and Definitions • Processors (Nodes) • Multicore – more than one processor on a chip, dual = 2, quad = 4, etc. • Hybrid – a main processor with one or more secondary processors for specific computations (aka. accelerator) • “Macro” Architecture • Massively Parallel Processing system (MPP) – Supercomputer with nodes, memory, networking tightly integrated • Cluster – A network of commodity machines connected by a network • Interconnect (between nodes) • Crossbar – all nodes connected through crossbar • Mesh/Torus – nodes connected in a grid • Tree – nodes connected in a (fat) tree

Hardware Comparisons • IBM Road Runner • IBM Blue Gene L/P • Sun Constellation • Cray XT5/h • Cluster Systems • Top500.org

IBM Roadrunner • # 1 – 1 PetaFlop • Hybrid blades • 1-AMD Dual-core Opteron 1.8 GHz / 2-PowerXCell 8i 3.2 Ghz • 6,948 / 12,960 processors • Infiniband and Gigabit Ethernet • Los Alamos

“I know how to make 4 horses pull a cart - I don't know how to make 1024 chickens do it.” Enrico Clementi - former IBM fellow

IBM Blue Gene L/P • # 2, 3, 6, 9, others – 478 TFlops / 450 TFlops • Large number of modest processors • PowerPC 440/450 – 700/850 Mhz • 212,992 / 163,840 cores • 3-D torus • Communication over the torus network • Lawrence Livermore National Lab, Argonne, NCAR, others

Sun Constellation – Ranger • # 4 – 326 TFlops • AMD Quad-core Opteron 2 GHz Blades • 62,976 cores • Full-Clos Infiniband • Texas Advanced Computing Center

Cray XT5 • “Adapt the system to the application” • Quad-Core AMD Opteron 2.1 GHz • 30,976 (XT4 - Oak Ridge National Lab, # 5 – 205 TFlops) • Cray SeaStar2 – 3-D Torus • XT5h – hybrid processors • AMD Opteron • Configurable FPGA accelerator • Oak Ridge (planned)

Clusters • 400 of the Top500.org • Many different vendors, configurations • Low cost, commodity systems • More management tools becoming available • Slower communication between nodes

Trends • Multicore – more processors on a chip • Hybrid processors • Accelerators for specific kinds of computation • More difficult to take advantage of • “Greenness” – Green500.org • Liquid cooling – Cray XT5 planned for Oak Ridge • More tools and systems integration • Blue Waters • Microsoft Windows HPC • Deskside supercomputers? • IBM BG/S • Cray CX1 • Mainstream customers – not just for research anymore • Financial • Engineering

References • Overview of Recent Supercomputers - 2007 Edition http://top500.org/2007_overview_recent_supercomputers • Cray XT5 product brochure http://www.cray.com/Products/XT/Product/Specifications.aspx • Sun Constellation system information http://www.sun.com/servers/hpc/sunconstellationsystem/ • IBM Journal of Research and Development, Volume 52, Number 1/2, 2008 • “TACC Supercomputer Performs Laser Cancer Surgery on Canine” HPCWire, May 27, 2008, Aaron Dubrow • “Researchers successfully simulate photosynthesis and design a better leaf” News Bureau: University of Illinois at Urbana-Chapaign, November 2007, Diana Yates • The Blue Brain Project http://bluebrain.epfl.ch • Blue Waters http://www.ncsa.uiuc.edu/BlueWaters/

Background and Definitions • Architectural classes • SIMD – single instruction, multiple data (vectorprocessors) – multiple processors in lock-step, each with its own set of data • MIMD – multiple instruction, multiple data – the bulk of High Performance Computing (HPC) systems • Memory • Shared – all nodes have access to same memory • Distributed – each node has its own memory • NUMA – non-uniform memory access – logically shared, physically distributed • Interconnect (between nodes) • Crossbar – all nodes connected through crossbar • Mesh/Torus – nodes connected in a grid • Tree – nodes connected in a (fat) tree

What’s a Supercomputer Good for Anyway?