IBM remains the undisputed king of the supercomputers.

According to the latest figures, Big Blue holds a 47.8 percent share of the top 500 supercomputers, and Hewlett-Packard comes in second place with 31.2 percent of systems.

The Top500 list, compiled by university researchers in the US and Germany, ranks supercomputer systems by performance as measured by teraflops, or trillions of computer calculations per second.

But even though supercomputer end users don't buy them for their energy efficiency, the Top500 list will begin to include power efficiency measures in its next list, due out June 2007. In recent years, energy and the labour costs of managing computer systems have exceeded the cost of the hardware itself.

"We are looking at teraflops per watt and we are starting to track that and will at least provide the numbers," said Erich Strohmaier, a staff scientist at Lawrence Berkeley National Laboratory in California, and one of the list compilers. However, next year's list will still be ranked by computing performance.

Rankings based on processor brand shifted significantly with AMD's Opteron processors taking market share from Intel processors. Intel's market share fell to 52.2 percent from 66.6 percent in the year ago survey, while AMD's doubled to 22.6 percent from 11 percent. IBM fell to third place despite seeing its share rise to 18.6 percent from 14.6 percent.

IBM claims the number one spot on the 500 list with its IBM BlueGene/L system, installed at the US Department of Energy’s Lawrence Livermore National Laboratory (LLNL) in California. It operates at a maximum processing speed of 280.6 teraflops per second.

Supercomputing capabilities have been growing faster than Moore's Law, said Jack Dongarra, a distinguished professor in the Innovative Computing Laboratory at the University of Tennessee at Knoxville, another one of the list creators. Moore's Law holds that computer processing power doubles every 18 months, but the supercomputing sector's has been doubling every 14 months.

Dongarra cites developments such as multiple core processing, enabling chips to handle several instructions simultaneously, and Gigabit Ethernet, moving data among a network of computers at 1 billion bits per second, for the surge in supercomputing power.

The aggregate processing power of all 500 systems on the latest list is 3.54 petaflops (petaflop =1,000 teraflops), from 2.79 petaflops in the June listing and 2.30 petaflops a year ago. .

Although HP's name doesn't appear on the list until supercomputer number 40, an AlphaServer system at the Los Alamos National Laboratory in New Mexico, HP and IBM are the only vendors with double-digit market share. Both of them lead in supercomputing because they lead in the industry standard x86 processor platform market, said Gordon Haff, an analyst at Illuminata.

"IBM sells a lot of different types of systems and there are a lot of x86 servers in the Top500," said Haff. "HP also has a very strong x86 line and in the Top500 space, vendors who can do some level of large scale integration and tend to have an advantage."

The US is home to the most supercomputing systems with 306, followed by Europe with 95, and Asia with 79.

The top five supercomputers are:

  1. BlueGene/L, Lawrence Livermore National Laboratory, US (IBM)
  2. Red Storm, Sandia National Laboratories, US (Cray)
  3. BGW, The Thomas J. Watson Research Center, US, (IBM)
  4. ASC Purple, Department of Energy/Lawrence Livermore National Laboratory, US (IBM)
  5. MareNostrum, Bareclona Computer Center, Spain (IBM)