Supercomputers/Systems/Sandia CTS-2 Nitro
USA · operational · hpc
Sandia CTS-2 Nitro
Also known as SNL/NNSA CTS-2 Nitro; Nitro
Operated by Sandia National Laboratories .
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
- 8.36 PFlop/s
- Rpeak
- 9.50 PFlop/s
- Rmax ÷ Rpeak
- 88.0%
- Cores
- 148,512
- Power
- -
- Per watt
- - 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 | - Dell PowerEdge servers (TOP500 label PowerEdge C6220), CTS-2 | Dell Technologies | - | Reported | top500.orgllnl.gov |
| CPU | - Intel Xeon Platinum 8480+ 56C 2GHz; 148,512 cores implies 2,652 processors | Intel | 2,652 estimated | Reported | top500.orgllnl.gov |
| Interconnect | Omni-Path Architecture Interconnect Fat tree · 100 Gb/s per port · About 1 microsecond Cornelis Networks Omni-Path | Cornelis Networks | - | Reported | top500.orgllnl.gov |
| Operating system | Tri-Lab Operating System Stack Operating systems Linux distribution, RHEL-derived, HPC-tuned · Open source, LLNL-maintained Linux/TOSS | Lawrence Livermore National Laboratory | - | Reported | top500.org |
The read
Sandia National Laboratories' CTS-2 cluster named Nitro, listed on TOP500 as SNL/NNSA CTS-2 Nitro and a sibling of Mead (sandia-cts2-mead) in the tri-lab Commodity Technology Systems-2 family (see also sandia-amber and sandia-stout). TOP500 gives Dell PowerEdge servers (labelled C6220) with Xeon Platinum 8480+ 56-core 2 GHz on Cornelis Networks Omni-Path under Linux/TOSS, installation year 2025, 148,512 cores (2,652 processors), Rmax 8.36 and Rpeak 9.50 PFlop/s (88 percent efficiency) and 71.7 TFlop/s on HPCG. It debuted at 193rd in November 2025 and was 216th in June 2026. LLNL's November 2023 article on the first CTS-2 systems supports the family (Dell Technologies, 4th Gen Intel Xeon Scalable, Omni-Path) but does not mention Nitro, and TOP500 is the only source for this machine's figures, so the tier is reported. The campus is not stated, so the site is left blank.
Timeline
Public list appearances
Pointers only: rank and edition, linking to the canonical entry. We do not reproduce list tables. See sourcing policy.
Change history
- 2026-10-18 Added Sandia CTS-2 Nitro
Further reading
Operating a supercomputer
Acceptance testing, why "installed" and "in production" are six months apart, and the machine lifecycle.
Inside a node
Latency-optimised versus throughput-optimised processors, NUMA, and the end of the host-to-device copy.
The interconnect
Topologies, why latency and tail behaviour matter more than bandwidth, and how the fabric market consolidated.