R14000 and R16000, which were used in a series of models from 1999 through 2006. SGI's first Itanium-based system was the short-lived SGI 750 workstation, launched in 2001. SGI's MIPS-based systems were not to be superseded until the launch of the Itanium 2-based Altix servers and Prism workstations some time later. Unlike the MIPS systems, which ran IRIX, the Itanium systems used SuSE Linux Enterprise Server with SGI enhancements as their operating system. SGI used Transitive Corporation's QuickTransit software to allow their old MIPS/IRIX applications to run (in emulation) on the new Itanium/Linux platform. In the server market the Itanium 2-based Altix eventually replaced the MIPS-based Origin product line. In the workstation market, the switch to Itanium was not completed before SGI exited the market. The Altix was the most powerful computer in the world in 2006, assuming that a "computer" is defined as a collection of hardware running under a single instance of an operating system. The Altix had 512 Itanium processors running under a single instance of Linux. A cluster of 20 machines was then the eighth-fastest supercomputer. All faster supercomputers were clusters, but none have as many FLOPS per machine. However, more recent supercomputers are very large clusters of machines that are individually less capable. SGI acknowledged this and in 2007 moved away from the "massive NUMA" model to clusters. Switch to Xeon Although SGI continued to market Itanium-based machines, its more recent machines were based on the Intel Xeon processor. The first Altix XE systems were relatively low-end machines, but by December 2006 the XE systems were more capable than the Itanium machines by some measures (e.g., power consumption in FLOPS/W, density in FLOPS/m3, cost/FLOPS). The XE1200 and XE1300 servers used a cluster architecture. This was a departure from the pure NUMA architectures of the earlier Itanium and MIPS servers. In June 2007, SGI announced the Altix ICE 8200, a blade-based Xeon system with up to 512 Xeon cores per rack. An Altix ICE 8200 installed at New Mexico Computing Applications Center (with 14336 processors) ranked at number 3 on the TOP500 list of November 2007. User base and core market Conventional wisdom holds that SGI's core market has traditionally been Hollywood visual effects studios. In fact, SGI's largest revenue has always been generated by government and defense applications, energy, and scientific and technical computing. In one case Silicon Graphics' largest single sale ever was to