Supercomputers Daniel Shin CS 147, Section 1 April 29, 2010

What is a Supercomputer  A computer that is at the frontline of current processing capacity, particularly speed of calculation  Today's supercomputer tend to become tomorrow's ordinary computer  Designed to perform complex calculations at super high speeds which would require a year or longer for a normal computer

Uses of Supercomputers Used for highly calculation-intensive tasks  Problems involving quantum physics  Weather forecasting  Climate research  Molecular modeling  Physical simulations

History of Supercomputers  Supercomputers were introduced in the 1960s  They were designed primarily by Seymour Cray at Control Data Corporation (CDC)  Early machines were basically very fast scalar processors Cray-1 supercomputer Cray-2 supercomputer

Measuring Performance FLOPS (FLoating point Operations Per Second) Usually prefixed by an SI unit of magnitude: megaFLOPS, gigaFLOPS, teraFLOPS, petaFLOPS, exaFLOPS Supercomputers are projected to reach 1 exaFLOPS (EFLOPS) in 2019 LINPACK Benchmark A software library for performing numerical linear algebra on digital computers written in FORTRAN

Comparisons 3.6GHz Pentium 4 1 gigaFLOPS (GFLOPS) 1.8GHz Opteron 3 gigaFLOPS (GFLOPS) IBM Roadrunner 1.1 petaFLOPS (PFLOPS) Cray Jaguar 1.75 petaFLOPS (PFLOPS)

Supercomputer Challenges Generates large amounts of heat and must be cooled Information cannot move faster than the speed of light between two parts of a supercomputer Seymour Cray's supercomputer designs attempted to keep cable runs as short as possible for this reason, hence the cylindrical shape of his Cray range of computers Supercomputers consume and produce massive amounts of data in a very short period of time

Supercomputer Challenges (cont.) Technologies developed for supercomputers include: Vector processing Liquid cooling Non-Uniform Memory Access (NUMA) Striped disks (the first instance of what was later called RAID) Parallel filesystems

Seymour Roger Cray Born September 28, 1925 in Chippewa Falls, Wisconsin His father was a civil engineer who is said to have fostered Cray's interest in science and engineering Cray's passion for building scientific computers led him to help start Control Data Corporation (CDC) in 1957 Recognized as “the father of supercomputing” “Anyone can build a fast CPU. The trick is to build a fast system.” – Seymour Cray

Cray Computers Cray is said to have frequently cited two important aspects to his design philosophy: remove heat, and ensure that all signals that are supposed to arrive somewhere at the same time do indeed arrive at the same time Cray was also said to have been proud of the cushions that surrounded his cylindrically shaped computers, atop the power supplies Cray Inc. is a supercomputer manufacturer based in Seattle, Washington It was founded in 1972 by computer designer Seymour Cray

Cray Computers (cont.) CDC 1604  The CDC 1604 was a 48-bit computer designed and manufactured by Seymour Cray and his team at the Control Data Corporation The 1604 is known as the first commercially successful transistorized computer Cray-1 The Cray-1 was a supercomputer designed, manufactured, and marketed by Cray Research One of the best known and most successful supercomputers in history The first Cray-1 system was installed at Los Alamos National Laboratory in 1976 Cray-1 with internals exposed

Cray Computers (cont.) Cray Jaguar In November 2009, the AMD Opteron-based Cray XT5 Jaguar at the Oak Ridge National Laboratory was announced as the fastest operational supercomputer Cray Jaguar performed at a sustained processing rate of 1.75 petaFLOPS, beating the IBM Roadrunner for the number one spot on the TOP500 list Future Development Cray, Inc. announced in December 2009 a plan to build a 1 exaFLOPS (EFLOPS) supercomputer by the end of the 2010s Jaguar XT5

Flynn's Taxonomy, Computer Architectures Single instruction single data steam (SISD) Single instruction multiple data steams (SIMD) Multiple instruction single data steam (MISD) Multiple instruction multiple data steams (MIMD)

Flynn's Taxonomy, Computer Architectures (cont.)

Single instruction single data steam (SISD) A sequential computer which exploits no parallelism in either the instruction or data streams Examples of SISD architecture: traditional uniprocessor machines like a PC or old mainframes

Single instruction multiple data steams (SIMD) A computer which exploits multiple data streams against a single instruction stream to perform operations which may be naturally parallelized Examples of SIMD architecture: an array processor or GPU

Multiple instruction single data steam (MISD) Multiple instructions operate on a single data stream Uncommon architecture which is generally used for fault tolerance Example of MISD architecture: the Space Shuttle flight control computer

Multiple instruction multiple data steams (MIMD) Multiple autonomous processors simultaneously executing different instructions on different data Distributed systems are generally recognized to be MIMD architectures