The Cray X1 is a

non-uniform memory access Non-uniform memory access (NUMA) is a computer memory design used in multiprocessing, where the memory access time depends on the memory location relative to the processor. Under NUMA, a processor can access its own local memory faster than non ...

vector processor In computing, a vector processor or array processor is a central processing unit (CPU) that implements an instruction set where its instructions are designed to operate efficiently and effectively on large one-dimensional arrays of data called ...

supercomputer manufactured and sold by Cray Inc. since 2003. The X1 is often described as the unification of the

Cray T90 The Cray T90 series (code-named ''Triton'' during development) was the last of a line of vector processing supercomputers manufactured by Cray Research, Inc, superseding the Cray C90 series. The first machines were shipped in 1995, and featured ...

Cray SV1 The Cray SV1 is a vector processor supercomputer from the Cray Research division of Silicon Graphics introduced in 1998. The SV1 has since been succeeded by the Cray X1 and X1E vector supercomputers. Like its predecessor, the Cray J90, the SV1 u ...

, and

Cray T3E The Cray T3E was Cray Research's second-generation massively parallel supercomputer architecture, launched in late November 1995. The first T3E was installed at the Pittsburgh Supercomputing Center in 1996. Like the previous Cray T3D, it was a ful ...

architectures into a single machine. The X1 shares the multistreaming processors, vector caches, and CMOS design of the SV1, the highly scalable distributed memory design of the T3E, and the high

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered ...

bandwidth and liquid cooling of the T90. The X1 uses a 1.2 ns (800 MHz) clock cycle, and 8-wide vector pipes in MSP mode, offering a peak speed of 12.8 gigaflops per processor. Air-cooled models are available with up to 64 processors. Liquid-cooled systems scale to a theoretical maximum of 4096 processors, comprising 1024 shared-memory nodes connected in a two-dimensional

torus In geometry, a torus (plural tori, colloquially donut or doughnut) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis that is coplanar with the circle. If the axis of revolution does not ...

network, in 32 frames. Such a system would supply a peak speed of 50

teraflops In computing, floating point operations per second (FLOPS, flops or flop/s) is a measure of computer performance, useful in fields of scientific computations that require floating-point calculations. For such cases, it is a more accurate me ...

. The largest unclassified X1 system was the 512 processor system at

Oak Ridge National Laboratory Oak Ridge National Laboratory (ORNL) is a U.S. multiprogram science and technology national laboratory sponsored by the U.S. Department of Energy (DOE) and administered, managed, and operated by UT–Battelle as a federally funded research an ...

, though this has since been upgraded to an X1E system. The X1 can be programmed either with widely used message passing software like

MPI MPI or Mpi may refer to: Science and technology Biology and medicine * Magnetic particle imaging, an emerging non-invasive tomographic technique * Myocardial perfusion imaging, a nuclear medicine procedure that illustrates the function of the hear ...

and

PVM Parallel Virtual Machine (PVM) is a software tool for parallel networking of computers. It is designed to allow a network of heterogeneous Unix and/or Windows machines to be used as a single distributed parallel processor. Thus large computatio ...

, or with shared-memory languages like

Unified Parallel C Unified Parallel C (UPC) is an extension of the C programming language designed for high-performance computing on large-scale parallel machines, including those with a common global address space (SMP and NUMA) and those with distributed memory ...

programming language or Co-array Fortran. The X1 runs an

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ef ...

called UNICOS/mp which shares more with the SGI

IRIX IRIX ( ) is a discontinued operating system developed by Silicon Graphics (SGI) to run on the company's proprietary MIPS workstations and servers. It is based on UNIX System V with BSD extensions. In IRIX, SGI originated the XFS file system ...

operating system than it does with the

UNICOS UNICOS is a range of Unix and after it Linux operating system (OS) variants developed by Cray for its supercomputers. UNICOS is the successor of the Cray Operating System (COS). It provides network clustering and source code compatibility la ...

found on prior generation Cray machines. In 2005, Cray released the X1E upgrade, which uses dual-core processors, allowing two quad-processor nodes to fit on a node board. The processors are also upgraded to 1150 MHz. This upgrade almost triples the peak performance per board, but reduces the per-processor memory and interconnect bandwidth. X1 and X1E boards can be combined within the same system. The X1 is notable for its development being partly funded by United States Government's

National Security Agency The National Security Agency (NSA) is a national-level intelligence agency of the United States Department of Defense, under the authority of the Director of National Intelligence (DNI). The NSA is responsible for global monitoring, collectio ...

(under the code name SV2). The X1 was not a financially successful productCray Inc. 10k-filing for December 31, 2005
/ref> and it seems doubtful that it or its successors would have been produced without this support.

References

External links

ORNL X1 evaluationCray Legacy ProductsCray X1E at top500.org
X1 Vector supercomputers Computer-related introductions in 2003 {{Super-compu-stub