The 25th TOP500 List was introduced during the International Supercomputer Conference (ISC2005) in Heidelberg, Germany.
The No. 1 position was again claimed by the BlueGene/L System, a joint development of IBM and DOE's National Nuclear Security Administration (NNSA) and installed at DOE's Lawrence Livermore National Laboratory in Livermore, Calif. BlueGene/L also occupied the No. 1 position on the last TOP500 list issued in November 2004. However, the system was doubled in size during the last six months and reached a new record Linpack benchmark performance of 136.8 TFlop/s ("teraflops" or trillions of calculations per second). This system, once completed, will again be doubled in size and is expected to remain the #1 Supercomputer in the world for the next few editions of the TOP500 list.
The pace of innovation and performance improvements seen at the very high end of scientific computing shows no sign of slowing down. This time, half of the TOP10 systems on the November 2004 TOP500 list were displaced by newly installed systems and the last 201 systems on the list from last November are now too small to be listed any longer.