IBM Linux cluster - Lightning

On July 12, 2004, NCAR's Scientific Computing Division (SCD) took delivery of Lightning, a large-scale, high-performance Linux cluster manufactured by IBM. The acquisition was part of SCD's five-year strategic plan to evaluate new technologies and find ways to deliver more cost-effective tools for advancing the frontiers of science at NCAR. It was NCAR's first Linux-based supercomputer.

The 1.1-teraflops system was considerably faster on a per-processor basis than Bluesky, which at the time was NCAR's flagship IBM p690 system. In benchmark tests, the Community Atmosphere Model ran 30% faster on Lightning than on Bluesky, while the Parallel Ocean Program ran 40% faster. One reason for this was that Lightning's Opteron processors, built by Advanced MicroDevices, had better memory bandwidth than Bluesky's POWER4 processors, and thus could run the data-hungry models more efficiently.

At the time, many of NCAR's university partners who used models such as the Community Climate System Model or the Weather Research and Forecast model had Linux-based systems. For the first time at NCAR, Lightning offered them the chance to build, test, and evaluate these codes in a full-scale Linux computing environment similar to their own.