Supercomputers/Systems/PSC Cray T3D
USA · operational · hpc
PSC Cray T3D
Also known as T3D MC256-8 at Pittsburgh
Operated by PSC at Pittsburgh Supercomputing Center .
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
- 25.3 GFlop/s
- Rpeak
- 38.4 GFlop/s
- Rmax ÷ Rpeak
- 65.9%
- Cores
- 256
- 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 T3D MC256-8 | Cray HPENYSE
rolls up to Hewlett Packard Enterprise | - | Reported | top500.orgen.wikipedia.org |
| CPU | - DEC Alpha EV4 149 MHz, 256 processing elements | Digital Equipment Corporation HPENYSE
rolls up to Hewlett Packard Enterprise | 256 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 T3D MC256-8 at the Pittsburgh Supercomputing Center installed in 1994 with 256 DEC Alpha EV4 149 MHz processors on a 3-D torus running UNICOS, 25.3 GFLOPS Rmax and 38.4 GFLOPS peak, 13th on the November 1994 list (15th in June 1994 at 21.4 GFLOPS). Wikipedia states that the first T3D delivered was a prototype installed at PSC in early September 1993 before the formal introduction on 27 September 1993, and PSC later hosted T3D MC512-8 and T3E systems. TOP500 is the only source for the figures here, so the tier is reported. The last list evidence is November 1994, which is recorded as the status date.
Timeline
Public list appearances
Pointers only: rank and edition, linking to the canonical entry. We do not reproduce list tables. See sourcing policy.
Site & facility
Change history
- 2026-10-09 Added PSC Cray T3D
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.
Every source cited on this page was readable, and none of them mentions this system. They are cited at page granularity, normally because no stable deep link could be found. That is a real weakness in this row and it is why the system carries a confidence tier below verified. See how this check works.
| Cited source | Result | Found on the page |
|---|---|---|
| en.wikipedia.org | does not name this system | - |
| top500.org | does not name this system | - |
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.