Supercomputers/Systems/Titan
USA · decommissioned · hpc
Titan
Also known as Cray XK7
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
- 17.59 PFlop/s
- Rpeak
- 27.11 PFlop/s
- Rmax ÷ Rpeak
- 64.9%
- Cores
- 560,640
- Power
- 8.21 MW
- Per watt
- 2.1 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 | - Cray XK7 | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | olcf.ornl.gov |
| Accelerator | NVIDIA Tesla K20X Accelerators CUDA (Kepler GK110) · 2,688C · 0.732 GHz · 28 nm · 235 W NVIDIA K20x | NVIDIA | 18,688 reported | Reported | olcf.ornl.gov |
| CPU | AMD Opteron 6274 (Interlagos) CPUs x86-64 · 16C · 2.2 GHz · 32 nm · 115 W Opteron 6274 16C 2.2GHz | AMD | 18,688 reported | Reported | olcf.ornl.gov |
| Interconnect | Cray Gemini Interconnect 3D torus · About 6 GB/s per direction per link · Around 1 microsecond Cray Gemini interconnect | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Verified | olcf.ornl.govtop500.org |
| Storage | Lustre Storage Parallel filesystem, separate metadata and object servers Spider, Lustre | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | olcf.ornl.gov |
| Cooling | Liquid-assisted air (in-cabinet coil) Cooling In-cabinet air, water-cooled coil · Roughly 20-45 kW per cabinet Cray XK7 cabinet: liquid-assisted air | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | olcf.ornl.gov |
| Operating system | Cray Linux Environment Operating systems Linux, Cray-customised · Proprietary layer over open-source Linux Cray Linux Environment | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | olcf.ornl.gov |
The read
Jaguar rebuilt with one NVIDIA K20X per node. The first US No. 1 whose performance came predominantly from GPUs, and the origin of the accelerator-share question this site exists to answer properly: by machine count Titan was one system, but by installed FLOPS it moved a large fraction of US leadership compute onto a single accelerator vendor in one procurement.
Timeline
- 2011 Announced source
- 2012-11 List debut at #1 (November 2012) source
- 2012-11 First operational source
- 2019-08 Retired after seven years as OLCF's flagship system, decommissioned August 1 source
- 2019-08 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
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 |
|---|---|---|
| olcf.ornl.gov | names system, part and count | AMD Opteron 6274 (Interlagos), Lustre · counts: 18688, 18688 |
| olcf.ornl.gov | names system, part and count | AMD Opteron 6274 (Interlagos), Cray Gemini · counts: 18688, 18688 |
Checked 2026-10-18 by pnpm verify. Re-run it and the table changes with the web.
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.