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 1540 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.
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 |
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
- 2018-06 List debut at #1 (June 2018) source
- 2018-06 First operational 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)
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.