ASCI White held the number 1 position for the fastest supercomputer in the world in November 2000 with 4.9 teraflop/s Linpack performance, according to top500.org. It had a theoretical processing speed of 12.3 teraflops, and it ran IBM's AIX operating system.

The IBM ASCI White system was a computer cluster based on IBM's commercial RS/6000 SP computer. It was made up of three individual systems—the 512-node White, the 28-node Ice, and the 68-node Frost. The 512 nodes were interconnected with each node containing sixteen 375 MHz IBM POWER3-II processors. In total, the ASCI White had 8,192 processors, 6 terabytes (TB) of memory, and 160 TB of disk storage. White weighed 106 tons and consumed 3 MW of electricity with a further 3 MW needed for cooling. It was almost exclusively used for large-scale computations requiring dozens, hundreds, or thousands of processors.

The system was completed in June 2000 and was transported from New York to California before it was officially dedicated at LLNL on August 15, 2001. It was decommissioned in 2006.