The TOP500 project ranks and details the 500 most powerful non-distributed computer systems in the world. The project was started in 1993 and publishes an updated list of the supercomputers twice a year. The first of these updates always coincides with the International Supercomputing Conference in June, and the second is presented at the ACM/IEEE Supercomputing Conference in November. The project aims to provide a reliable basis for tracking and detecting trends in high-performance computing and bases rankings on HPL, a portable implementation of the high-performance LINPACK benchmark written in Fortran for distributed-memory computers.
China currently dominates the list with 229 supercomputers, leading the second place (United States) by a record margin of 121. Since June 2018, the American Summit is the world's most powerful supercomputer, reaching 143.5 petaFLOPS on the LINPACK benchmarks.
The TOP500 list is compiled by Jack Dongarra of the University of Tennessee, Knoxville, Erich Strohmaier and Horst Simon of the National Energy Research Scientific Computing Center (NERSC) and Lawrence Berkeley National Laboratory (LBNL), and from 1993 until his death in 2014, Hans Meuer of the University of Mannheim, Germany.
In the early 1990s, a new definition of supercomputer was needed to produce meaningful statistics. After experimenting with metrics based on processor count in 1992, the idea arose at the University of Mannheim to use a detailed listing of installed systems as the basis. In early 1993, Jack Dongarra was persuaded to join the project with his LINPACK benchmarks. A first test version was produced in May 1993, partly based on data available on the Internet, including the following sources:
The information from those sources was used for the first two lists. Since June 1993, the TOP500 is produced bi-annually based on site and vendor submissions only.
Since 1993, performance of the No. 1 ranked position has grown steadily in accordance with Moore's law, doubling roughly every 14 months. As of June 2018 , Summit was fastest with an Rpeak of 187.6593 PFLOPS. For comparison, this is over 1,432,513 times faster than the Connection Machine CM-5/1024 (1,024 cores), which was the fastest system in November 1993 (twenty-five years prior) with an Rpeak of 131.0 GFLOPS.
As of November 201864-bit, mostly (all Intel-based, except for three) based on x86-64 CPUs (Intel EMT64 and AMD AMD64 instruction set architecture), with few exceptions (all based on reduced instruction set computing (RISC) architectures). Thirteen supercomputers are based on the Power ISA used by IBM POWER microprocessors (plus one new POWER9-based in June 2019) and six (only four as of June 2019) on Fujitsu-designed SPARC64 chips (one of which – the K computer – was 1st in 2011 without any GPUs (and is still 3rd on the HPCG list). One computer is based on seemingly related Chinese designs: Sunway SW26010 also using Chinese co-processors; the latter ascended to 1st in 2016 (it has since been superseded by an IBM POWER-based system). Further, a few computers use another non-US design, the Japanese PEZY-SC (based on the British ARM) as an accelerator paired with Intel's Xeon., all supercomputers on TOP500 are
In recent years heterogeneous computing, mostly using Nvidia's graphics processing units (GPU) or Intel's x86-based Xeon Phi as coprocessors, has dominated the TOP500 because of better performance per watt ratios and higher absolute performance; it is almost required to make the top 10 or the top spot; the only major recent exception being the aforementioned K computer and Sunway TaihuLight. Tianhe-2 is also an interesting exception, as while it did use accelerators (just not GPUs), i.e. Xeon Phi, US sanctions blocked the upgrade, but still the upgraded Tianhe-2A is faster with non-US-based Matrix-2000, accelerators which where exploited ahead of schedule. Frontera supercomputer, ranked 5th, based on 28-core (56-thread) Intel Xeon Platinum is also an exception, as it was measured without help of GPUs which were later added, but it has two subsystems, both with Nvidia GPUs, and one of them additionally with POWER9 CPUs, and the other liquid immersion cooling.
Two computers which first appeared on the list in 2018 are based on architectures never before seen on the Top500. One was a new x86-64 microarchitecture from Chinese vendor Sugon, using Hygon Dhyana CPUs (a collaboration between AMD and the Chinese, based on Zen) and is ranked 38th, and the other was the first ever ARM-based computer on the list (then upgraded for June 2019) – using Cavium ThunderX2 CPUs. Before the ascendancy of 32-bit x86 and later 64-bit x86-64 in the early 2000s, a variety of RISC processor families made up most TOP500 supercomputers, including RISC architectures such as SPARC, MIPS, PA-RISC, and Alpha.
All the fastest supercomputers in the decade since the Earth Simulator supercomputer have used operating systems based on Linux. Since November 2017 , all the listed supercomputers use an operating system based on the Linux kernel.
Since November 2015, no computer on the list runs Windows. In November 2014, Windows Azure cloud computer was no longer on the list of fastest supercomputers (its best rank was 165 in 2012), leaving the Shanghai Supercomputer Center's Magic Cube as the only Windows-based supercomputer on the list, until it also dropped off the list. It was ranked 436 in its last appearance on the list released in June 2015, while its best rank was 11 in 2008. There are no longer any Mac OS computers on the list. It had at most five such systems at a time, one more than the Windows systems that came later, while the total performance share for Windows was higher. The relative performance share of the whole list was however similar, and never high for either.
It has been well over a decade since MIPS systems dropped entirely off the list but the Gyoukou supercomputer that jumped to 4th place in November 2017 (after a huge upgrade) has MIPS as a small part of the coprocessors. Use of 2,048-core coprocessors (plus 8× 6-core MIPS, for each, that "no longer require to rely on an external Intel Xeon E5 host processor") make the supercomputer much more energy efficient than the other top 10 (i.e. it is 5th on Green500 and other such ZettaScaler-2.2-based systems take first three spots). At 19.86 million cores, it is by far the biggest system: almost double that of the best manycore system in the TOP500, the Chinese Sunway TaihuLight, ranked 3rd.
From the 52nd list (November 2018) to the 53rd list (June 2019), the Xeon Platinum-based Frontera is the only new supercomputer in the top 10 (at number 5) and the upgraded POWER9-based Lassen moved from 11th to 10th.Titan and Sequoia became the last Blue Gene/Q models to drop out of the top10; they had been ranked 9th and 10th in the 52nd list (and 1st and 2nd in the November 2012, 40th list) and are now 12th and 13th.
"For the first time, all 500 systems deliver a petaflop or more on the High Performance Linpack (HPL) benchmark, with the entry level to the list now at 1.022 petaflops." However, for a different benchmark "Summit and Sierra remain the only two systems to exceed a petaflop on the HPCG benchmark, delivering 2.9 petaflops and 1.8 petaflops, respectively. The average HPCG result on the current list is 213.3 teraflops, a marginal increase from 211.2 six months ago."
Of the top 11 computers in the 53rd Top500 list, six are in the top 25 of the June 2019 Green500 list (most energy-efficient supercomputers):
|Summit||IBM Power System AC922||POWER9, Tesla V100||InfiniBand EDR||IBM||Oak Ridge National Laboratory
United States, 2018
|Sierra||IBM Power System S922LC||POWER9, Tesla V100||InfiniBand EDR||IBM||Lawrence Livermore National Laboratory
United States, 2018
|Sunway TaihuLight||Sunway MPP||SW26010||Sunway||NRCPC||National Supercomputing Center in Wuxi
|Tianhe-2A||TH-IVB-FEP||Xeon E5-2692 v2, Matrix-2000||TH Express-2||NUDT||National Supercomputing Center in Guangzhou
|Frontera||Dell C6420||Xeon Platinum 8280 (subsystems with e.g. POWER9 CPUs and Nvidia GPUs added after benchmarking)||InfiniBand HDR||Dell EMC||Texas Advanced Computing Center
United States, 2019
|Piz Daint||Cray XC50||Xeon E5-2690 v3, Tesla P100||Aries||Cray||Swiss National Supercomputing Centre
|Trinity||Cray XC40||Xeon E5-2698 v3, Xeon Phi 7250||Aries||Cray||Los Alamos National Laboratory
United States, 2015
|AI Bridging Cloud Infrastructure||PRIMERGY CX2550 M4||Xeon Gold 6148, Tesla V100||InfiniBand EDR||Fujitsu||National Institute of Advanced Industrial Science and Technology
|SuperMUC||ThinkSystem SD530||Xeon Platinum 8174 (plus not benchmarked e.g. 32 cloud GPU nodes with Tesla V100)||Intel Omni-Path||Lenovo||Leibniz Supercomputing Centre
|Lassen||IBM Power System S922LC||POWER9, Tesla V100||InfiniBand EDR||IBM||Lawrence Livermore National Laboratory
United States, 2018
Numbers below represent the number of computers in the TOP500 that are in each of the listed countries.
|Country/Region||Nov 2018||Jun 2018||Nov 2017||Jun 2017||Jun 2016||Nov 2015||Jun 2015||Nov 2014||Jun 2014||Nov 2013||Jun 2013||Nov 2012||Jun 2012||Nov 2011||Jun 2011||Nov 2010||Jun 2010||Nov 2009||Jun 2009||Nov 2008||Jun 2008||Nov 2007|
|United Arab Emirates||1|
By number of systems as of November 2018:
Note: All operating systems of the TOP500 systems use Linux, but Linux above is generic Linux.
In November 2014, it was announced that the United States was developing two new supercomputers to exceed China's Tianhe-2 in its place as world's fastest supercomputer. The two computers, Sierra and Summit, will each exceed Tianhe-2's 55 peak petaflops. Summit, the more powerful of the two, will deliver 150-300 peak petaflops. On 10 April 2015, US government agencies banned selling chips, from Nvidia, to supercomputing centers in China as "acting contrary to the national security ... interests of the United States"; and Intel Corporation from providing Xeon chips to China due to their use, according to the US, in researching nuclear weapons – research to which US export control law bans US companies from contributing – "The Department of Commerce refused, saying it was concerned about nuclear research being done with the machine."
On 29 July 2015, President Obama signed an executive order creating a National Strategic Computing Initiative calling for the accelerated development of an exascale (1000 petaflop) system and funding research into post-semiconductor computing.
In June 2016, Japanese firm Fujitsu announced at the International Supercomputing Conference that its future exascale supercomputer will feature processors of its own design that implement the ARMv8 architecture. The Flagship2020 program, by Fujitsu for RIKEN plans to break the exaflops barrier by 2020 (and "it looks like China and France have a chance to do so and that the United States is content – for the moment at least – to wait until 2023 to break through the exaflops barrier.") These processors will also implement extensions to the ARMv8 architecture equivalent to HPC-ACE2 that Fujitsu is developing with ARM Holdings.
In June 2016, Sunway TaihuLight became the No. 1 system with 93 petaflop/s (PFLOP/s) on the Linpack benchmark.
Inspur has been one of the largest HPC system manufacturer based out of Jinan, China. As of May 2017 , Inspur has become the third manufacturer to have manufactured 64-way system – a record which has been previously mastered by IBM and HP. The company has registered over $10B in revenues and have successfully provided a number of HPC systems to countries outside China such as Sudan, Zimbabwe, Saudi Arabia, Venezuela. Inspur was also a major technology partner behind both the supercomputers from China, namely Tianhe-2 and Taihu which lead the top 2 positions of Top500 supercomputer list up to November 2017. Inspur and Supermicro released a few platforms aimed at HPC using GPU such as SR-AI and AGX-2 in May 2017.
In November 2017, for the second time in a row there were no system from the USA under the TOP3. #1 and #2 were installed in China, a system in Switzerland at #3, and a new system in Japan was #4 pushing the top US system to #5.
In June 2018, Summit, an IBM-built system at the Oak Ridge National Laboratory (ORNL) in Tennessee, USA, took the #1 spot with a performance of 122.3 petaflop/s (PFLOP/s), and Sierra, a very similar system at the Lawrence Livermore National Laboratory, CA, USA took #3. These two system took also the first two spots on the HPCG benchmark. Due to Summit and Sierra, the USA took back the lead as consumer of HPC performance with 38.2% of the overall installed performance while China was second with 29.1% of the overall installed performance. For the first time ever the leading HPC manufacturer is not a US company. Lenovo took the lead with 23.8 percent of systems installed. It is followed by HPE with 15.8 percent, Inspur with 13.6 percent, Cray with 11.2 percent, and Sugon with 11 percent. 
On 18 March 2019, the United States Department of Energy and Intel announced the first exaFLOP supercomputer would be operational at Argonne National Laboratory by the end of 2021. The computer, named "Aurora" is to be delivered to Argonne by Intel and Cray.
On 7 May 2019, The U.S. Department of Energy announced a contract with Cray Inc. to build the "Frontier" supercomputer at Oak Ridge National Laboratory. Frontier is anticipated to be operational in 2021 and, with a performance of greater than 1.5 exaflops, should then be the world's most powerful computer.
As of June 2019, all TOP500 systems deliver a petaflop or more on the High Performance Linpack (HPL) benchmark, with the entry level to the list now at 1.022 petaflops.
Some major systems are not listed on the list. The largest example is the NCSA's Blue Waters which publicly announced the decision not to participate in the list because they do not feel it accurately indicates the ability for any system to be able to do useful work. Other organizations decide not to list systems for security and/or commercial competitiveness reasons. Additional purpose-built machines that are not capable or do not run the benchmark were not included, such as RIKEN MDGRAPE-3 and MDGRAPE-4.
Similarly (non-SIMD-style) vector processors (NEC-based such as the Earth simulator that was fastest in 2002) have also fallen off the list. Also the Sun Starfire computers that occupied many spots in the past now no longer appear.
Frontera is unique among the top systems in the world in its use of Intel Xeon processors to provide its primary computing power. [..] Frontera will add a NVIDIA GPU subsystem later this summer, providing further performance.
Powering the ZettaScaler-2.2 is the PEZY-SC2. The SC2 is a second-generation chip featuring twice as many cores – i.e., 2,048 cores with 8-way SMT for a total of 16,384 threads. [..] The first-generation SC incorporated two ARM926 cores and while that was sufficient for basic management and debugging its processing power was inadequate for much more. The SC2 uses a hexa-core P-Class P6600 MIPS processor which share the same memory address as the PEZY cores, improving performance and reducing data transfer overhead. With the powerful MIPS management cores, it is now also possible to entirely eliminate the Xeon host processor. However, PEZY has not done so yet.