Supercomputers/Systems/NCAR CDC 6600
USA · decommissioned · hpc
NCAR CDC 6600
Also known as CDC 6600 serial 7
Operated by NCAR at NCAR Mesa Laboratory (Boulder) .
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
- -
- Rpeak
- -
- Rmax ÷ Rpeak
- -
- Cores
- 1
- 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 | - Control Data Corporation CDC 6600, serial number 7 | Control Data Corporation | - | Reported | cisl.ucar.edu |
| CPU | - CDC 6600 central processor with ten peripheral processors, 60-bit words, 10 MHz clock | Control Data Corporation | 1 reported | Reported | cisl.ucar.edu |
| Operating system | - NCAR-developed operating system and FORTRAN 66 compiler | NCAR | - | Reported | cisl.ucar.edu |
The read
NCAR's CDC 6600, serial number 7, delivered in late December 1965 after the Computing Facility advisory panel approved the purchase in August 1964. NCAR's own history page says it had 65,000 60-bit words of memory, a 10 MHz clock and ten peripheral processors, and ran an operating system NCAR wrote itself because CDC's software was behind schedule. It was first installed in a University of Colorado building at 3215 Marine Street, Boulder, and moved to the Mesa Laboratory in December 1966. It was decommissioned in May 1977 after more than eleven years, with the CDC 7600 as its successor. The site is recorded as the Mesa Laboratory for simplicity. NCAR is the only source fetched, so the tier is reported and no FLOPS figure is recorded.
Site & facility
NCAR Mesa Laboratory (Boulder)
- Location
- Boulder, CO, USA
- Commissioned
- 1986
Change history
- 2026-10-09 Added NCAR CDC 6600
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 |
|---|---|---|
| cisl.ucar.edu | 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.
Programming a supercomputer
The software stack beneath the application, and why the OS is now a sovereignty signal as much as a technical choice.