IBM's Roadrunner and Cray's Jaguar have retained their No. 1 and No. 2 rankings on the Top500 supercomputer list released twice yearly.
Roadrunner, the first machine to break the petaflop barrier a year ago, registered 1.105 petaflops to top the list. Built in 2008, the system is housed at the U.S. Department of Energy's (DOE) Los Alamos National Laboratory.
Jaguar, installed at DOE's Oak Ridge National Laboratory, reached 1.059 petaflops/s. Both machines led the Top500 pack with these results last November.
Eight of the top 10 systems are housed in the United States, while two machines are based in Germany. In third spot was another Big Blue machine--a new BlueGene/P system called Jugene installed at the Forschungszentrum Juelich (FZJ) in Germany. It achieved 825.5 teraflop/s and has a theoretical peak performance of just above 1 petaflop/s, according to the Top500 Web site.
FZJ is also home to Juropa, the new No. 10 system which registered 274.8 teraflop/s. It is built from Bull Novascale and Sun Microsystem SunBlade x6048 servers.
Two other high-performance computing (HPC) systems in the top 10 are new--the Kraken, a Cray XT5 machine installed at the National Institute for Computational Sciences at the University of Tennessee at No. 6, and the IBM BlueGene/P system called Dawn installed at DOE’s Lawrence Livermore National Laboratory at No. 9.
The only Asian supercomputer in the previous top 10 ranking--the Shanghai Supercomputer Center's Dawning 5000A--came in at No. 15.
Overall, there were significant gains in performance, said the Top500 team. The last system on the latest list would have been listed at No. 274 in the November rankings.
The United States' share of supercomputers stood unchanged from the previous list at 291, while the European share dropped to 145 from November's 151. Asia was home to 49 of the HPC systems, up from 47 previously.
The next best Asian performer was HP's EKA - Cluster Platform 3000 BL460c at the Computational Research Laboratories owned by the Tata Group from India, which occupied the 18th spot. Japan's Earth Simulator Center by NEC, was No. 22 on the list.
While IBM is ahead by overall installed performance, its share of the total number of systems on the latest Top500 list was 24 short of rival Hewlett-Packard's 212 systems.
A total of 399 systems, up from 379 previously, are powered by Intel processors. According to an Intel statement Tuesday, 33 of these machines tap on the Xeon 5500 launched in March.
IBM Power processors were used in 55 systems, down from 60 last November, while AMD's share of the systems decreased by 16 to the current 43.