Chinese supercomputer still No. 1, ORNL’s Titan No. 2

A Chinese supercomputer kept its top ranking, and Titan at Oak Ridge National Laboratory stayed at No. 2 in a Top 500 ranking of the world’s most powerful supercomputers released Monday morning.

The top two spots were unchanged from the semiannual rankings released five months ago in June, when Tianhe-2, a supercomputer developed by China’s National University of Defense Technology, bumped Titan from the top spot. The ORNL supercomputer had been named No. 1 one year ago.

The rankings released Monday at the SC13 conference in Denver, Colo., said Tianhe-2 is capable of performing 33.86 petaflops. That’s 33.86 quadrillion calculations per second, on what is known as a Linpack benchmark test.

Titan is a Cray XK7 system that achieved 17.59 petaflops. Titan is one of the most energy-efficient systems on the list, consuming a total of 8.21 megawatts and delivering 2.143 gigaflops per watt, a press release said.

It’s the 42nd edition of the TOP500 list.

The appearance of Tianhe-2 in the top spot in June, two years ahead of the expected deployment, marked China’s first return to the No. 1 position since November 2010, when Tianhe-1A was the top system. It could be a wakeup call for the United States, Jack Dongarra, a Top 500 co-author, said this summer.

“Back in 2001, China had no supercomputers—zero,” said Dongarra, who is also a University of Tennessee faculty member and distinguished research staff member in ORNL’s Computer Science and Mathematics Division. “Today, they are No. 2 behind the U.S.”

Computerworld reported in June that China spent about $290 million on TH-2. Titan is a $100 million machine.

Dongarra said this summer that China could stay on top for a few years unless the Japanese, who have been No. 1 in the past, or Europeans catch up first. In a report he wrote after an international forum in China at the end of May, Dongarra said the next large acquisition of a supercomputer for the U.S. Department of Energy will not be until 2015.

In an interview posted by NPR in October, ORNL Director Thom Mason, who has expressed concern about the long-term impacts of the automatic federal budget cuts known as sequestration, said the ability to replace ORNL’s Titan supercomputer is moving further and further into the future. Researchers had hoped to replace Titan in 2017.

“The issue is not so much who’s No. 1 in the horse race,” Mason told NPR. “But we think it’s important for the U.S. to always be amongst that group that is pushing the envelope.”

Sequoia, an IBM BlueGene/Q system installed at Lawrence Livermore National Laboratory, is again the No. 3 system on the list released Monday. It was first delivered in 2011 and achieved 17.17 petaflops on the Linpack benchmark.

Fujitsu’s K computer installed at the RIKEN Advanced Institute for Computational Science, or AICS, in Kobe, Japan, is the No. 4 system with 10.51 petaflops.

Mira, a BlueGene/Q system installed at Argonne National Laboratory, is No. 5 with 8.59 petaflops. ORNL, Lawrence Livermore National Laboratory, and Argonne National Laboratory are all U.S. Department of Energy labs.

The press release said the new entry in the TOP10 is at No. 6: Piz Daint, a Cray XC30 system installed at the Swiss National Supercomputing Centre, or CSCS, in Lugano, Switzerland. It’s now the most powerful system in Europe. Piz Daint achieved 6.27 petaflops.

Piz Daint is also the most energy-efficient system in the TOP10, consuming 2.33 megawatts and delivering 2.7 gigaflops per watt, the release said.

Rounding out the TOP10 are Stampede at the Texas Advanced Computing Center of the University of Texas, Austin, which slipped to No. 7; a BlueGene/Q system called JUQEEN installed at the Forschungszentrum Juelich in Germany, which is No. 8; Vulcan, another IBM BlueGene/Q system at Lawrence Livermore National Laboratory, which is No. 9; and at No. 10, the third system in Europe, the SuperMUC, installed at Leibniz Rechenzentrum in Germany.

The total combined performance of all 500 systems on the list is 250 petaflops, the release said. Half of the total performance is achieved by the top 17 systems on the list, with the other half of total performance spread among the remaining 483 systems.

See the full list here.

Here is more information from the press release:

Other highlights from the November 2013 TOP500 List, which can be found at www.top500.org, include:

• In all, there are 31 systems with performance greater than a petaflop/s on the list, an increase of five compared to the June 2013 list.
• The No. 1 system, Tianhe-2, and the No. 7 system, Stampede, are using Intel Xeon Phi processors to speed up their computational rate. The No. 2 system Titan and the No. 6 system Piz Daint are using NVIDIA GPUs to accelerate computation.
• A total of 53 systems on the list are using accelerator/co-processor technology, unchanged from June 2013. Thirty-eight (38) of these use NVIDIA chips, two use ATI Radeon, and there are now 13 systems with Intel MIC technology (Xeon Phi).
• Intel continues to provide the processors for the largest share (82.4 percent) of TOP500 systems.
• Ninety-four percent of the systems use processors with six or more cores and 75 percent have processors with eight or more cores.
• The number of systems installed in China has now stabilized at 63, compared with 65 on the last list. China occupies the No. 2 position as a user of HPC, behind the U.S. but ahead of Japan, UK, France, and Germany. Due to Tianhe-2, China this year also took the No. 2 position in the performance share, topping Japan.
• The last system on the newest list was listed at position 363 in the previous TOP500.

Geographical observations

• The U.S. is clearly the leading consumer of HPC systems with 265 of the 500 systems (253 last time). The European share (102 systems compared to 112 last time) is still lower than the Asian share (115 systems, down from 118 last time).
• Dominant countries in Asia are China with 63 systems (down from 65) and Japan with 28 systems (down from 30).
• In Europe, UK, France, and Germany, are almost equal with 23, 22, and 20 respectively.

About the TOP500 List

The first version of what became today’s TOP500 list started as an exercise for a small conference in Germany in June 1993. Out of curiosity, the authors decided to revisit the list in November 1993 to see how things had changed. About that time they realized they might be on to something and decided to continue compiling the list, which is now a much-anticipated, much-watched and much-debated twice-yearly event.

The TOP500 list is compiled by Dongarra and Hans Meuer of the University of Mannheim in Germany, and Erich Strohmaier and Horst Simon of Lawrence Berkeley National Laboratory.

Note: This story was last updated at 9:45 a.m.