Supercomputers/Systems/Summit
USA · decommissioned · mixed
Summit
Also known as OLCF-4
Operated by Oak Ridge National Laboratory at Oak Ridge Leadership Computing Facility .
Researched with AI assistance, checked by scripts. These rows were researched by AI agents reading public operator, laboratory and vendor sources, appended by scripts and checked by automated validation; no subject-matter expert has reviewed them (how this site is made). A mechanical second-reader pass has since fetched every cited source: 1350 of 1581 systems have a readable citation that names them, and 64 are genuinely weakly sourced. Every claim carries its source and a confidence tier. Treat anything below verified as a lead, not a citation.
Measured performance
- Rmax
- 148.6 PFlop/s
- Rpeak
- 200.8 PFlop/s
- Rmax ÷ Rpeak
- 74.0%
- Cores
- 2,414,592
- Power
- 10.10 MW
- Per watt
- 14.7 GF/W
Figures are as last publicly reported for the configuration described below, not a live measurement. Where a system was upgraded in place, the post-upgrade configuration is shown and the earlier one appears in the timeline.
How it compares
Ranked against the other machines in this dataset that report the same figure: those that first came into service within two years of Summit, and those in USA. Computed from our tables; a metric is ranked only when at least eight peers report it.
| Metric | Value | Against its era | Against its country |
|---|---|---|---|
| Rmax | 148.6 PFlop/s | #2 of 223 · top 1% | #8 of 332 · top 2% |
| Energy efficiency | 14.7 GF/W | #16 of 133 · top 11% | #31 of 162 · top 19% |
| Rmax ÷ Rpeak | 74.0 % | #71 of 216 · top 33% | #171 of 331 · bottom 49% |
| Power draw | 10,096 kW | #3 of 137 · top 1% | #4 of 171 · top 2% |
Every metric is ranked largest-first, so a high power-draw rank means a big power draw, not a good one. Rmax ÷ Rpeak uses HPL-measured results only. Rankings move as machines are added; they describe this dataset, not the world.
What this machine is made of
One row per supplier relationship. “Supplier at build” is the company that shipped the part at the time; where that company has since been acquired, the parent it rolls up to today is shown beside it. That distinction is what makes ticker-level aggregation possible across a thirty-year dataset.
| Role | Part | Supplier at build | Quantity | Confidence | Source |
|---|---|---|---|---|---|
| Integrator | - IBM Power System AC922 | IBM | - | Reported | olcf.ornl.govibm.com |
| Accelerator | NVIDIA Tesla V100 Accelerators CUDA (Volta GV100) · 5,120C · 1.53 GHz · 12 nm · 300 W NVIDIA Volta GV100, 6 per node | NVIDIA | 27,648 reported | Reported | olcf.ornl.govibm.com |
| CPU | IBM POWER9 22C CPUs POWER · 22C · 3.07 GHz · 14 nm · 190 W IBM POWER9 22C 3.07GHz | IBM | 9,216 reported | Reported | olcf.ornl.govibm.com |
| Interconnect | Mellanox InfiniBand EDR Interconnect Fat tree · 100 Gb/s per 4x port · About 0.9 microseconds Dual-rail Mellanox EDR InfiniBand | Mellanox NVDANASDAQ
rolls up to NVIDIA | - | Reported | olcf.ornl.govibm.com |
| Storage | IBM Spectrum Scale ESS (GPFS) Storage Parallel filesystem (GPFS), erasure-coded declustered RAID · 250 PB on Summit (Alpine) · About 2.5 TB/s Alpine, IBM Spectrum Scale | IBM | - | Reported | olcf.ornl.govibm.com |
| Cooling | Direct-to-chip cold plate Cooling Cold plate on the package, air for the remainder · Removes roughly 50-80 percent of node heat to liquid IBM Power System AC922: water-cooled cold plates on CPU and GPU | IBM | - | Reported | olcf.ornl.govibm.com |
| Operating system | Red Hat Enterprise Linux Operating systems Linux distribution · Open source, commercial support subscription Red Hat Enterprise Linux for POWER | Red Hat | - | Reported | olcf.ornl.govibm.com |
Engineering, funding and access
What Summit runs on, who paid for it and how people get time on it. Each line carries who said it and when.
Hardware
| Item | Detail | As of | Basis | Source |
|---|---|---|---|---|
| Compute nodes | 4,608 nodesEach node had 2 IBM POWER9 CPUs and 6 NVIDIA V100 GPUs, 27,648 GPUs in total; OLCF text elsewhere says about 4,600 | 2024 | Operator stated | olcf.ornl.gov |
| Storage capacity | 250 PBAlpine file system; node-local non-volatile memory acts as a burst buffer | 2024 | Operator stated | olcf.ornl.gov |
| Interconnect and topology | Dual-rail Mellanox EDR InfiniBandOLCF describes a non-blocking fat tree with 25 GB/s node injection bandwidth; NVLink links CPUs and GPUs inside a node | 2024 | Operator stated | olcf.ornl.govtop500.org |
Software
| Item | Detail | As of | Basis | Source |
|---|---|---|---|---|
| Parallel filesystem | Alpine, 250 PB IBM Spectrum Scale (GPFS) with about 2.5 TB/s sequential bandwidth; HPSS for archive | 2024 | Operator stated | olcf.ornl.gov |
| Programming and software stack | RHEL 7.4 with IBM XL compilers, nvcc, ESSL, CUBLAS 9.2 and IBM Spectrum MPIAs reported with the TOP500 submission | 2019 | Operator stated | top500.org |
Funding
| Item | Detail | As of | Basis | Source |
|---|---|---|---|---|
| Funded by | U.S. Department of EnergyFunded under the CORAL collaboration of Oak Ridge, Argonne and Livermore | 2014-11 | Operator stated | science.osti.gov |
| Procurement | CORAL award announced 14 Nov 2014: $325 million to build Summit at ORNL and Sierra at LLNL, both on IBM Power, NVIDIA Volta GPUs and Mellanox interconnectThe $325 million is for both machines combined | 2014-11-14 | Operator stated | science.osti.gov |
Access
| Item | Detail | As of | Basis | Source |
|---|---|---|---|---|
| How researchers get time | OLCF Early Science program from 1 Oct 2018, then INCITE allocations from 1 Jan 2019 | 2019 | Operator stated | olcf.ornl.gov |
Results
| Item | Detail | As of | Basis | Source |
|---|---|---|---|---|
| Notable result | Linpack of 148.6 PFlop/s, HPCG of 2.926 PFlop/s and measured power draw of 10.1 MW on the TOP500 submission | 2018-11 | Operator stated | top500.org |
The read
IBM POWER9 hosts with six NVIDIA V100s per node, coherently attached over NVLink rather than PCIe: the last leadership-class system to use a non-x86, non-Arm host CPU. Its retirement in late 2024 removed the largest remaining block of POWER installed base from the graph in a single step, which is visible as a discontinuity on the CPU-architecture share chart and is worth flagging whenever that chart is quoted.
Timeline
- 2014 Announced source
- 2014-11-14 DOE announces the CORAL award of $325 million to build Summit at ORNL and Sierra at LLNL on IBM Power9, NVIDIA Volta and Mellanox technology source
- 2018-06 List debut at #1 (June 2018) source
- 2018-06 First operational source
- 2018-10-01 Early Science projects begin running on Summit ahead of INCITE allocations in 2019 source
- 2024-11 Retired after six years of operation source
- 2024-11 Decommissioned source
Public list appearances
Pointers only: rank and edition, linking to the canonical entry. We do not reproduce list tables. See sourcing policy.
Site & facility
Oak Ridge Leadership Computing Facility
- Location
- Oak Ridge, TN, USA
- Utility
- Tennessee Valley Authority
- Cooling
- Direct liquid cooling (warm water)
- Commissioned
- 1993
Change history
- 2026-09-22 Gained a Green500 rank pointer (#58 on the 2023-11 list)
Nearby in scale
The machines closest to Summit by Rmax, smaller to larger.
- ABCI 3.0 · Japan, operational · 145.1 PFlop/s
- MareNostrum 5 ACC · Spain, operational · 138.2 PFlop/s
- NIPA(NHN Cloud)-CL-1 · South Korea, operational · 137.4 PFlop/s
- Maximus-02 · USA, operational · 156.1 PFlop/s
- Discovery 6 · USA, operational · 164.2 PFlop/s
- ISEG2 · Netherlands, operational · 202.4 PFlop/s
Related systems
Same site
- Andes (OLCF) · USA, operational, 2020
- Frontier TDS · USA, operational, 2021
- Frontier · USA, upgraded, 2022
- Gaea · USA, operational, 2023
- Titan · USA, decommissioned, 2012
- Discovery (ORNL) · USA, planned
Same operator
- Lux (ORNL) · USA, planned
- Jaguar · USA, upgraded, 2009
- Phoenix (ORNL) · USA, decommissioned, 2003
- Cheetah (ORNL) · USA, decommissioned, 2002
- Intel Paragon XP/S 150 · USA, decommissioned, 1995
- ORNL Paragon XP/S 35 · USA, operational, 1992
Same accelerator
- ABCI · Japan, decommissioned, 2018
- Ansel (LLNL) · USA, operational, 2018
- Circe · USA, operational, 2018
- CLAIX-2018 · Germany, decommissioned, 2018
- COBRA · Germany, decommissioned, 2018
- Govorun · Russia, upgraded, 2018
Source check
We fetched this system's own citations and recorded whether each page actually mentions it. This is a corroboration signal, not a fact check, and it is published so you can see how well the sourcing holds up rather than take it on trust.
| Cited source | Result | Found on the page |
|---|---|---|
| ibm.com | does not name this system | - |
| olcf.ornl.gov | names system, part and count | IBM POWER9 22C, Mellanox InfiniBand EDR, IBM Spectrum Scale ESS (GPFS) · counts: 27648 |
Checked 2026-10-18 by pnpm verify. Re-run it and the table changes with the web.
Related news
- Summit retired after six years at Oak Ridge · Oak Ridge Leadership Computing FacilityThe retirement removes the largest remaining block of IBM POWER installed base from the graph in a single step, which is visible as a discontinuity on any CPU-architecture share chart.
Further reading
Inside a node
Why accelerators exist, what the memory hierarchy costs, and how the CPU and accelerator merged onto one package.
Power and cooling
Why air ran out at 20 kW a rack, how warm-water cooling removes the chillers, and what PUE conceals.
Operating a supercomputer
Acceptance testing, why "installed" and "in production" are six months apart, and the machine lifecycle.