The Janus supercomputer was originally comprised of 1368 compute nodes, each containing 12 cores, for a total 16,416 available cores. Janus could achieve 184 TFLOPS (Trillion Floating Point Operations). It has since been decommissioned, succeeded by Summit.

Here are some details about Janus when it was installed:

  • Default OS - Redhat 6 Enterprise.
  • 1368 compute nodes (4 nodes per Chassis, 342 Chassis.) [Current size: 800 compute nodes]
  • 16416 total cores (Each node contains two hex-core 2.8Ghz Intel Westmere processors for 12 cores per node.) [Current size 9600 cores].
  • 2GB of RAM per core.
  • 24GB RAM per node (about 20GB free with the base image loaded) for 32TB total system RAM.
  • Approximately 800TB of high performance storage is accessible via a Lustre filesystem.

Janus nodes were interconnected via a non-blocking QDR Infiniband high performance network theoretically capable of 40Gbps. The management network was 10Gbps and the cluster connected to the CU Research Network via multiple 10Gbps links. Funding for Janus was provided by NSF-MRI Grant CNS-0821794, the University of Colorado and the National Center for Atmospheric Research.


If you used Janus to support your research, please include the following citation: "This work utilized the Janus supercomputer, which is supported by the National Science Foundation (award number CNS-0821794) and the University of Colorado Boulder. The Janus supercomputer is a joint effort of the University of Colorado Boulder, the University of Colorado Denver and the National Center for Atmospheric Research."