Supercomputers/Systems/Met Office Cray T3E900
United Kingdom · operational · hpc
Met Office Cray T3E900
Also known as T3E900 at Bracknell
Operated by Met Office .
Phase 1 seed dataset, compiled by hand. These rows were built from public operator, laboratory and vendor sources. A mechanical second-reader pass has since fetched every cited source: 1263 of 1345 systems have a readable citation that names them, and 56 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
- 430.3 GFlop/s
- Rpeak
- 756.0 GFlop/s
- Rmax ÷ Rpeak
- 56.9%
- Cores
- 840
- 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 | - Cray Research Cray T3E900 | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | top500.orgen.wikipedia.org |
| CPU | - DEC Alpha EV5 450 MHz, 840 processing elements | Digital Equipment Corporation HPENYSE
rolls up to Hewlett Packard Enterprise | 840 reported | Reported | top500.org |
| Interconnect | - Cray 3-D torus interconnect | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | top500.org |
| Operating system | - UNICOS | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | top500.org |
The read
TOP500 lists a Cray T3E900 at the UK Meteorological Office installed in 1997 with 840 DEC Alpha EV5 450 MHz processors on a 3-D torus running UNICOS, third on the November 1997 list at 430.3 GFLOPS Rmax and 756 GFLOPS peak (the system page later shows 531 GFLOPS and the June 1998 list 450 GFLOPS, still fourth). Wikipedia's Met Office article lists a 1997 Cray T3E 900/1200 at 430 GFLOPS as the Office's operational forecasting machine. TOP500 also lists a larger 876-processor Met Office T3E900 on later lists, which is not separately recorded here. The 430.3 GFLOPS figure is the ranked November 1997 value. The tier is reported. The June 1998 list is the last evidence of this entry.
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
- 2026-10-09 Added Met Office Cray T3E900
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 |
|---|---|---|
| en.wikipedia.org | names system only | - |
| top500.org | names system only | - |
Checked 2026-10-13 by pnpm verify. Re-run it and the table changes with the web.
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.