The SGI Origin 200/2000 is a cache-coherent non-uniform memory access (ccNUMA) multiprocessor designed and manufactured by Silicon Graphics, Inc. The Origin system was designed from the ground up as a multiprocessor capable of scaling to both small and large processor counts without any cost, bandwidth, or latency cliffs. The Origin system consists of up to 512 nodes interconnected by a highly scalable Craylink network. Each node consists of one or two R10000 processors and up to 4 GB of coherent memory. Each node also connects to the scalable XIO IO subsystem. This paper discusses the motivation for building the Origin 200/2000 and describes its architecture and implementation.