Supercomputers/Systems/El Capitan
USA · operational · classified
El Capitan
Also known as ATS-4
Operated by Lawrence Livermore National Laboratory at Livermore Computing Center.
Phase 1 seed dataset — under review. These rows were compiled by hand from public operator, laboratory and vendor sources, and have not yet been through a second-reader verification pass. Every claim carries its source and a confidence tier; treat anything below verified as a lead, not a citation.
Measured performance
- Rmax
- 1.74 EFlop/s
- Rpeak
- 2.75 EFlop/s
- Rmax ÷ Rpeak
- 63.4%
- Cores
- 11,039,616
- Power
- 29.58 MW
- Per watt
- 58.9 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 | — HPE Cray EX255a | Hewlett Packard Enterprise | — | Verified | llnl.govhpe.com |
| Accelerator | AMD Instinct MI300A Accelerators AMD Instinct MI300A | AMD | — | Verified | llnl.govhpe.com |
| CPU | AMD 4th Gen EPYC 24C (in MI300A) CPUs AMD 4th Gen EPYC 24C 1.8GHz (integrated in MI300A) | AMD | — | Reported | llnl.govhpe.com |
| Interconnect | HPE Slingshot-11 Interconnect Slingshot-11 | Hewlett Packard Enterprise | — | Verified | llnl.govhpe.com |
| Storage | HPE Cray ClusterStor E1000 Storage Lustre on ClusterStor E1000 | Hewlett Packard Enterprise | — | Reported | llnl.govhpe.com |
| Cooling | Direct liquid cooling, warm water Cooling 100% direct liquid cooled cabinet | Hewlett Packard Enterprise | — | Reported | llnl.govhpe.com |
| Operating system | HPE Cray Operating System Operating systems HPE Cray Operating System | Hewlett Packard Enterprise | — | Reported | llnl.govhpe.com |
The read
Built on the MI300A APU, which collapses the CPU and accelerator roles onto one package with unified HBM3 — there is no host-to-device copy. That has a direct consequence for this dataset: the CPU and accelerator edges point at parts made of the same silicon by the same supplier, and any accelerator-share analysis that counts CPU sockets separately will double-count. Our methodology page states how we handle it. Stockpile stewardship workload.
Timeline
- 2019 Announced source
- 2024-11 List debut at #1 (November 2024) source
- 2024-11 First operational 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
Livermore Computing Center
- Location
- Livermore, CA, USA
- Cooling
- Direct liquid cooling (warm water)
- Commissioned
- 1996