Supercomputers/Systems/Littlebear (NCAR CM-5)
USA · decommissioned · hpc
Littlebear (NCAR CM-5)
Also known as Connection Machine 5; NCAR CM-5/32
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
- 4.1 GFlop/s
- Rmax ÷ Rpeak
- -
- Cores
- 32
- 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 | - Thinking Machines Corporation CM-5 (32 nodes, control processor Littlebear) | Thinking Machines | - | Reported | cisl.ucar.edu |
| CPU | Thinking Machines CM-5 vector node CPUs SPARC + custom vector · 1C · 0.032 GHz Thinking Machines CM-5, 32 nodes each with a SPARC and four vector units | Thinking Machines | 32 reported | Reported | cisl.ucar.edu |
| Storage | Scalable Disk Array Storage Direct-attached disk nodes on the CM-5 data network, NFS-mountable Scalable disk array with 24 GB for user data | Thinking Machines | - | Reported | cisl.ucar.edu |
| Operating system | Thinking Machines CMost Operating systems Unix (TMC-proprietary variant) · Proprietary CMost, a Sun-based Unix operating system | Thinking Machines | - | Reported | cisl.ucar.edu |
The read
A 32-node Thinking Machines CM-5 that arrived at NCAR on 21 April 1993, bought for $1.47 million ($46,000 per node) with DARPA funds. Each node had four vector units and a SPARC microprocessor; NCAR gives 32 MB of memory per node (1 GB total), 128 MFLOPS peak per node, a scalable disk array holding 24 GB of user data and the CMost operating system. NCAR named its control processor Littlebear. NCAR's supercomputing-history table lists the peak as about 4.1 GFLOPS and a commissioning date of 1 March 1993 while the narrative page says the machine arrived in April, so April 1993 is recorded. It was decommissioned in October 1996 per the narrative (the table says November). NCAR is the only source fetched, so the tier is reported.
Site & facility
NCAR Mesa Laboratory (Boulder)
- Location
- Boulder, CO, USA
- Commissioned
- 1986
Change history
- 2026-10-09 Added Littlebear (NCAR CM-5)
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 |
|---|---|---|
| cisl.ucar.edu | names system, part and count | Thinking Machines CM-5 vector node, Thinking Machines CMost, Scalable Disk Array · counts: 32 |
Checked 2026-10-13 by pnpm verify. Re-run it and the table changes with the web.
Further reading
Inside a node
Latency-optimised versus throughput-optimised processors, NUMA, and the end of the host-to-device copy.
Operating a supercomputer
Acceptance testing, why "installed" and "in production" are six months apart, and the machine lifecycle.
Programming a supercomputer
The software stack beneath the application, and why the OS is now a sovereignty signal as much as a technical choice.