SCIENCE

The 29th edition of the closely watched TOP500 list of the world’s fastest supercomputers shows a lot of shuffling among the top-ranked systems and the largest turnover among list entries in the history of the TOP500 project. The Top500 list, which is published every June and November, was released today at the International Supercomputing Conference (ISC ’07) in Dresden, Germany. The new list, as well as previous lists, can be found on the Web at www.top500.org. For the fourth straight time, the BlueGene/L System development by IBM and DOE’s National Nuclear Security Administration (NNSA) and installed at DOE’s Lawrence Livermore National Laboratory in Livermore, Calif., claimed the No. 1 spot. The BlueGene/L reached a Linpack benchmark performance of 280.6 TFlop/s (“teraflops” or trillions of calculations per second). Two other systems exceeded the level of 100 TFlop/s: the upgraded Cray XT4/XT3 at DOE’s Oak Ridge National Laboratory, ranked No. 2 with a benchmark performance of 101.7 TFlop/s; and Sandia National Laboratory’s Cray Red Storm system, which ranked third at 101.4 TFlop/s. Two new IBM BlueGene/L systems entered the Top 10, at the New York Center for Computational Science in Stony Brook, NY, (ranked No. 5) and at the Computational Center for Nanotechnology Innovations at Rensselaer Polytechnic Institute in Troy, NY, (ranked No. 7). These two systems represent the largest supercomputing installations in an academic setting. Also new to the Top 10 is a Dell system at the National Center for Supercomputing Applications, ranked No. 8. The fastest supercomputer in Europe is an IBM JS21 cluster at the Barcelona Supercomputing Center in Spain, which ranked No. 9 at 62.63 TFlop/s. Rounding out the Top 10 is a new SGI system installed at the Leibniz Computer Center in Munich, Germany, with performance of 56.52. TFlop/s. The highest ranked Japanese system is located at the Tokyo Institute of Technology and ranks No. 14 on the list. This system is a cluster integrated by NEC based on Sun Fire x4600 with Opteron processors, ClearSpeed accelerators and an InfiniBand interconnect. Highlights from the 29th TOP500 list include:

• The performance needed to make it onto the list increased to 4.005 TFlop/s on the Linpack benchmark, compared to 2.737 TFlop/s six months ago.
• The system ranked No. 500 on the current list would have held position No. 216 only six months ago when the last list was produced. This is the largest turnover rate between lists in the TOP500 project’s 15-year history.
• Total combined performance for all 500 systems reached 4.92 PFlop/s (“petaflops” or thousand “teraflops”), compared to 3.54 PFlop/s six months ago and 2.79 PFlop/s one year ago.

Other trends of interest:

• A total of 289 systems (57.8 percent) now use Intel processors, up slightly from six months ago from 261 systems and 52.5 percent. The second most-commonly used processors are the AMD Opteron family, with 105 systems (21 percent), down from 113 systems (22.6 percent) six months ago. Eighty-five systems (17 percent) use IBM Power processors, down from 93 systems (18.6 percent) six months ago.
• Dual core processors are the dominant chip architecture. Intel’s Woodcrest dual core chip showed the most growth, with 205 systems using this chip compared to 31 six months ago. Another 90 systems use Opteron dual core processors, up from 75 six months ago.
• Clusters remain the most common architecture in the TOP500 list. The list has 373 clusters, a stable 74.6 percent of all systems.InfiniBand is growing strongly, but is till behind Gigabit Ethernet as the most common internal interconnect technology, with 127 systems using InfiniBand (up from 78) compared to 207 for Gigabit Ethernet (down from 211).For quite some time IBM and Hewlett-Packard have sold the bulk of the systems at all performance levels, but the current list shows HP now has the lead in the total number of systems on the list with 40.6 percent (up from 31.6 percent six months ago). IBM now has 38.4 percent of the systems (down from 47.2 percent). No other manufacturer has more than 5 percent of the systems on the list, but Dell came close at 4.8 percent.IBM remains the clear leader of the TOP500 list in performance with 41.9 percent of installed performance (down from 49.5 percent) compared to HP with 24.5 percent (up from 16.5).
• Other manufacturers with more than 5 percent of the performance category are: Dell (9 percent), Cray (7.3 percent), and SGI (5.7 percent), each of which benefit from large systems in the Top 10.
• The U.S. remains the leading consumer of HPC systems with 281 of the 500 systems. The European share (127 systems, up from 95) continued to rebound and is again larger than the Asian share (72, down from 79).
• Dominant countries in Asia are Japan with 23 systems (down from 30) and China with 13 systems (down from 18). In Europe, the UK has established itself as the leader, with 43 systems (up from 32). Germany is second with 24 systems (up from 19).
• The average age of a system in the TOP500 list is only 1 year and 2 months. 60 percent have been installed or upgraded this year and 23 percent were installed or upgraded last year.
• IBM is the clear leader among the Top 50 systems, with 46 percent of the systems and 49 percent of performance. HP is currently absent from the Top 50.

The TOP500 list is compiled by Hans Meuer of the University of Mannheim, Germany; and Erich Strohmaier and Horst Simon of NERSC/Lawrence Berkeley National Laboratory; and Jack Dongarra of the University of Tennessee, Knoxville.