ASCI White was a supercomputer at the Lawrence Livermore Laboratory in California.
It was a computer cluster based on IBM's commercial RS/6000 SP computer. 512 of these machines were connected together for ASCI White, with 16 processors per node and 8,192 processors in total with 6 terabytes of memory and 160 terabytes of disk storage. Despite these formidable statistics, each processor was slow by 2006 standards, operating at a mere 375 MHz. Therefore, it was almost exclusively used for computations requiring dozens of processors. The computer weighed 106 tons and consumed 3 MW of electricity with a further 3 MW needed for cooling. It had a theoretical processing speed of 12.3 teraflops. The system ran IBM's AIX operating system.
ASCI White was made up of three individual systems, the 512 node White, the 28 node Ice and the 68 node Frost.
The system was built in Poughkeepsie, New York. Completed in June 2000 it was transported to specially built facilities in California and officially dedicated on August 15, 2001. Claimed performance was 12,300 gigaflops, although this was not achieved in the widely accepted LINPACK tests. The system cost $110 million.
It was built as stage three of the Accelerated Strategic Computing Initiative (ASCI) started by the U.S. Department of Energy and the National Nuclear Security Administration to build a simulator to replace live WMD testing following the moratorium on testing started by President George H. W. Bush in 1992 and extended by Bill Clinton in 1993.
The machine was decommissioned beginning July 27, 2006.