Supercomputing is an interesting field, which, unlike the turbulent PC scenario, is associated with slow but steady improvements. However, every year a new performance record ends up being created. This year ASCI White from IBM replaced Intel’s ASCI Red as the fastest supercomputer. Another aspect of supercomputing is the cost of computing. Constant endeavors have been on to bring this down. Beowulf clusters have been used to build supercomputers cheap, and a price-performance ratio of less than $1,000 per GFlops (giga, or one billion, floating point operations per second) has been reached during the year. Traditional supercomputers cost about $10,000 per GFlops, while Beowulf clusters till now have costed around $3,000 per GFlops.

ASCI White

Installed at the Lawrence Livermore National Laboratory (LLNL), US, this massive machine is part of the Advanced Strategic Computer Initiative (ASCI) of the US Department of Energy. It’s used to test nuclear weapons without actually conducting explosions, and other energy-related research. The machine has 512 nodes, each containing 16 Power3-III CPUs running at 375 MHz each, totaling to 8,192 processors. It has 6.2 terabytes of memory, and 160 terabytes of storage. ASCI White takes up floor space equivalent to two basketball courts, and weighs 106 tons. Its maximal performance, measured using the Linpack benchmark (see box "How to benchmark a supercomputer?"), is 4,938 GFlops.

Is it built from ground up? Not exactly. The machine is a scaled-up version of IBM’s RS/6000 SP (Scalable Parallel) Power 3 server. Some of the fastest supercomputers in the world today use this architecture.

ASCI Red

Built last year, this system is installed at Sandia National Labs, Albuquerque, US, and is employed in research by the US Department of Energy. It clocks a maximal performance of 2,379 GFlops, and is the second-fastest supercomputer. This is a distributed memory MIMD (multiple instruction, multiple data), message-passing machine. That is, each CPU in the machine has its own memory, and is connected to other CPUs to enable data exchange between their respective memories. The machine executes several instruction streams in parallel on different data, which are related to each other. The ASCI Red has 9,632 PentiumPro processors, 594 GB RAM, a total of 2 terabytes of storage space, and occupies 1,600 square feet of floor space.

ASCI Blue-Pacific

The number three supercomputer is also installed at LLNL, and clocks a maximal performance of 2,144 GFlops. It’s a hypercluster of 1,464 IBM SP uniform memory access SMPs. Each of these nodes has four IBM PowerPC 604e processors running at 332 MHz each. The system has 2.6 terabytes of memory and 75 terabytes of storage space.