There were no changes in the ranking of the top ten supercomputers for the first time since the list was first compiled in 1993. But shifts at the top are expected within the next six to 12 months.
Within a year "there will be a number of new entries in the U.S. from Argonne, Lawrence Livermore and Oak Ridge National Labs," said Dongarra.
"There are plans for several 10+ petaflops systems in the U.S., and it will be interesting to see which systems come next and at what levels," said Strohmaier who also is a researcher at Lawrence Berkeley National Laboratory.
While the rankings did not change, the top system on the list, Japan’s K Computer, jumped from 8.16 to 10.51 petaflops on the Linpack benchmark the list uses. The system now uses a whopping 705,024 SPARC64 processor cores from Fujitsu, and does not use any GPUs or other accelerators.
The next closest system, China's Tianhe-1A, hit 2.57 petaflops. The largest U.S. system, called Jaguar and installed at the Oak Ridge National Lab, is third on the list at 1.75 petaflops.
Among other trends the average Top 500 system now uses 18,383 cores, up from 15,520 six months ago and 13,071 a year ago. Currently 62 percent of the systems use processors with six or more cores.
Processor and system vendors had generally stable rankings compared to the previous list.
Intel processors are used in 384 systems (76.8 percent), down from 386 systems (77.2 percent) six months ago. AMD follows with 63 systems (12.6 percent), down from 66.
IBM's Power processors came in third with chips in 49 systems (9.8 percent), up from 45.
IBM kept its lead in systems with 223 computers (44.6 percent) on the list compared to archrival Hewlett-Packard with 140 systems (28.0 percent). Cray, SGI, Bull and Appro follow with 5.4, 3.3, 3.0 and 2.6 percent respectively.
In terms of power use, 29 systems on the list use more than one megawatt. The K Computer that tops the list consumes 12.66 MW, but is one of the most efficient systems on the list at 830 Mflops/watt. The most energy efficient system is the IBM BlueGene/Q at 2,029 Mflops/watt.
Gigabit Ethernet continues to be the most widely used interconnect among the Top 500 which are mainly cluster architectures. However Infiniband is edging toward parity with use in 213 systems, up from 208, compared to 223 for Gbit Ethernet, down from 230.
However, Infiniband-based systems account for almost twice as much performance at 28.7 petaflops compared to Gigabit Ethernet at 14.2 petaflops.