NCAR CDC 7600

Also known as CDC 7600 serial 12

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: 0.0 GFlop/s
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 7600, serial number 12	Control Data Corporation	-	Reported	cisl.ucar.edu en.wikipedia.org
CPU	- CDC 7600 central processor, 60-bit words, 27 ns clock	Control Data Corporation	1 reported	Reported	cisl.ucar.edu
Operating system	- NCAR-developed operating system and FORTRAN 70 compiler shared with the 6600	NCAR	-	Reported	cisl.ucar.edu

The read

NCAR chose the CDC 7600 over an IBM System 360 Model 195 after benchmarks in early 1970 and took delivery of serial number 12 in May 1971. NCAR's page gives a small core memory of 65,536 60-bit words and a 27 ns clock, about five times the speed of the 6600, and notes that its low mean time to failure forced NCAR to build very good job and file recovery procedures. NCAR's supercomputing-history table lists 36 MFLOPS peak, which is recorded as operator-stated. It ran almost 12 years, was used as a front end to the Cray-1A from 1977, and was replaced in spring 1983 by a second Cray-1A. Wikipedia independently notes that both Lawrence Livermore and NCAR reported 7600 failures several times a day. The tier is reported.

Timeline

1971-05 First operational source
1983-04 Decommissioned source

Site & facility

NCAR Mesa Laboratory (Boulder)

Location: Boulder, CO, USA
Commissioned: 1986

cisl.ucar.edu cisl.ucar.edu

Change history

2026-10-09 Added NCAR CDC 7600

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	does not name this system	-
cisl.ucar.edu	names system only	-

Checked 2026-10-13 by pnpm verify. Re-run it and the table changes with the web.