Cray X1
| Industry | Supercomputing |
|---|---|
| Founded | 2003 |
| Products | Cray X1, Cray X1E supercomputers |
The Cray X1 is a vector processor supercomputer featuring a non-uniform memory access architecture, designed and marketed by Cray Inc. since 2003. This system merges design elements from the Cray T90, Cray SV1, and Cray T3E, incorporating the SV1's multistreaming processors and vector cache technology, the T3E's scalable distributed memory model, and the T90's high-bandwidth memory complemented by liquid cooling.
Each processor operates with an 800 MHz (1.2 ns) clock cycle and utilizes eight-wide vector pipelines to achieve a performance of up to 12.8 gigaflops. The air-cooled variants accommodate as many as 64 processors, whereas liquid-cooled configurations can expand to 4096 processors distributed across 1024 shared-memory nodes arranged in a two-dimensional torus topology, reaching maximum computational speeds of 50 teraflops. The most extensive unclassified deployment was a 512-processor setup at Oak Ridge National Laboratory, which was subsequently upgraded to an X1E system.
Programming on the X1 is supported through message passing frameworks such as MPI and PVM, alongside shared-memory languages including Unified Parallel C and Co-array Fortran. The system runs on the UNICOS/mp operating system, which is more closely derived from SGI's IRIX than from earlier Cray UNICOS versions.
In 2005, Cray released the X1E enhancement, which introduced dual-core processors clocked at 1150 MHz and enabled two quad-processor nodes per board. This upgrade nearly tripled peak board-level performance but resulted in decreased memory and interconnect bandwidth on a per-processor basis. Both X1 and X1E boards can operate together within the same system environment.
Development of the X1 received partial funding from the United States Government's National Security Agency under the project name SV2. Although technologically advanced, the X1 did not achieve commercial success and likely depended on government backing to support its production.