Cray X-MP
Encyclopedia
The Cray X-MP was a supercomputer
Supercomputer
A supercomputer is a computer at the frontline of current processing capacity, particularly speed of calculation.Supercomputers are used for highly calculation-intensive tasks such as problems including quantum physics, weather forecasting, climate research, molecular modeling A supercomputer is a...

 designed, built and sold by Cray Research
Cray
Cray Inc. is an American supercomputer manufacturer based in Seattle, Washington. The company's predecessor, Cray Research, Inc. , was founded in 1972 by computer designer Seymour Cray. Seymour Cray went on to form the spin-off Cray Computer Corporation , in 1989, which went bankrupt in 1995,...

. It was announced in 1982 as the "cleaned up" successor to the 1975 Cray-1
Cray-1
The Cray-1 was a supercomputer designed, manufactured, and marketed by Cray Research. The first Cray-1 system was installed at Los Alamos National Laboratory in 1976, and it went on to become one of the best known and most successful supercomputers in history...

, and was the world's fastest computer from 1983 to 1985. The principal designer was Steve Chen.

Description

The X-MP's main improvement over the Cray-1 was that it was a shared-memory parallel
Parallel computing
Parallel computing is a form of computation in which many calculations are carried out simultaneously, operating on the principle that large problems can often be divided into smaller ones, which are then solved concurrently . There are several different forms of parallel computing: bit-level,...

 vector processor
Vector processor
A vector processor, or array processor, is a central processing unit that implements an instruction set containing instructions that operate on one-dimensional arrays of data called vectors. This is in contrast to a scalar processor, whose instructions operate on single data items...

, the first such computer from Cray Research. It housed two CPUs in a mainframe that was near identical in outside appearance, to the Cray-1.

The X-MP CPU had a faster 9.5 nanosecond
Nanosecond
A nanosecond is one billionth of a second . One nanosecond is to one second as one second is to 31.7 years.The word nanosecond is formed by the prefix nano and the unit second. Its symbol is ns....

 clock cycle (105 MHz), compared to 12.5 ns for the Cray-1A. It was built from bipolar
Bipolar junction transistor
|- align = "center"| || PNP|- align = "center"| || NPNA bipolar transistor is a three-terminal electronic device constructed of doped semiconductor material and may be used in amplifying or switching applications. Bipolar transistors are so named because their operation involves both electrons...

 gate-array integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

s containing 16 emitter-coupled logic
Emitter-coupled logic
In electronics, emitter-coupled logic , is a logic family that achieves high speed by using an overdriven BJT differential amplifier with single-ended input, whose emitter current is limited to avoid the slow saturation region of transistor operation....

 gate
Logic gate
A logic gate is an idealized or physical device implementing a Boolean function, that is, it performs a logical operation on one or more logic inputs and produces a single logic output. Depending on the context, the term may refer to an ideal logic gate, one that has for instance zero rise time and...

s each. The CPU was very similar to the Cray-1 CPU in architecture, but had better memory bandwidth (with two read ports and one write port to the main memory instead of one) and improved chaining support. Each CPU had a theoretical peak performance of 200 MFLOPS, for a peak system performance of 400 MFLOPS.

The X-MP supported 2 or 4 million 64-bit words (16 or 32 MB) of main memory in 16 or 32 banks, respectively. Memory bandwidth was significantly improved over the Cray-1—instead of one port for both reads and writes, there were now two read ports, one write port, and one dedicated to I/O. The main memory was built from 4 Kbit bipolar SRAM ICs.

In 1984, improved models of the X-MP were announced, consisting of one-, two, and four-processor systems. The top-end system was the X-MP/48, which contained four CPUs for a theoretical peak system performance of over 800 MFLOPS. The CPUs in these models introduced vector gather/scatter
Gather-scatter (vector addressing)
Gather-scatter is a type of memory addressing that often arises when addressingvectors in sparse linear algebra operations. It is thevector-equivalent of register indirect addressing, with gather involving indexedreads and scatter indexed writes...

 memory reference instructions to the product line. The amount of main memory supported was increased to a maximum of 16 million words, depending on the model. The main memory was built from bipolar or MOS SRAM ICs, depending on the model.

The system initially ran the proprietary Cray Operating System
Cray Operating System
The Cray Operating System was Cray Research's proprietary operating system for its Cray-1 and Cray X-MP supercomputers, and those platforms' main OS until replaced by UNICOS in the late 1980s...

 (COS) and was object-code compatible with the Cray-1. UniCOS
Unicos
UNICOS is the name of a range of Unix-like operating system variants developed by Cray for its supercomputers. UNICOS is the successor of the Cray Operating System . It provides network clustering and source code compatibility layers for some other Unixes. UNICOS was originally introduced in 1985...

 (a UNIX System V derivative) ran through a guest operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

 facility. UniCOS became the main OS from 1986 onwards. The DOE
United States Department of Energy
The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...

 ran the Cray Time Sharing System
Cray Time Sharing System
The Cray Time Sharing System, also known in the Cray user community as CTSS, was developed as an operating system for the Cray-1 or Cray X-MP line of supercomputers. CTSS was developed by the Los Alamos Scientific Laboratory in conjunction with the Lawrence Livermore Laboratory...

 OS instead. See the Software section for the Cray 1 for a more detailed elaboration of software (language compiler, assembler, OSes, and applications) as X-MPs and 1s were mostly compatible.

Extended Architecture series

Cray Research announced the X-MP Extended Architecture series in 1986. The EA series CPU had an 8.5 ns clock cycle (117 MHz), and was built from macrocell array
Macrocell array
A macrocell array is an approach to the design and manufacture of ASICs. Essentially, it is a small step up from the otherwise similar gate array, but rather than being a prefabricated array of simple logic gates, the macrocell array is a prefabricated array of higher-level logic functions such as...

 and gate array ICs. The EA series extended the width of the A and B registers to 32 bits and performed 32-bit address arithmetic, increasing the amount of memory theoretically addressable to 2 billion words. The largest configuration produced was 64 million words of MOS SRAM in 64 banks. For compatibility with existing software written for the Cray-1 and older X-MP models, 24-bit addressing was also supported. Each EA series CPU's peak performance was 234 MFLOPS. For a four-processor system, the peak performance was 942 MFLOPS.

I/O subsystem

The I/O subsystem could have two to four I/O processors with a total of 2 to 32 disk storage units. The DD-39 and DD-49 hard drives each stored 1.2 GB with 5.9 MB/s and 9.8 MB/s transfer rates, respectively. Optional solid state drives were available with 256, 512 or 1024 MB capacities with transfer rates of 100 to 1,000 MB/s per channel.

Pricing

A 1984 X-MP/48 cost about US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....

15 million plus the cost of disks
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...

. In 1985 Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...

 purchased a Cray X-MP/24 for $10.5 million along with eight DD-49 1.2 GB drives for an additional $1 million. They received $1.5 million of trade-in credit for their Cray-1.

Successors

The Cray-2
Cray-2
The Cray-2 was a four-processor ECL vector supercomputer made by Cray Research starting in 1985. It was the fastest machine in the world when it was released, replacing the Cray Research X-MP designed by Steve Chen in that spot...

, a completely new design, was introduced 1985. A very different compact four-processor design with from 64 MW to 512 MW (512 MB to 4 GB) of main memory, it was specified to 500 MFLOPS but was slower than the X-MP on certain calculations due to its high memory latency.

The X-MP-succeeding Cray Y-MP
Cray Y-MP
The Cray Y-MP was a supercomputer sold by Cray Research from 1988, and the successor to the company's X-MP. The Y-MP retained software compatibility with the X-MP, but extended the address registers from 24 to 32 bits. High-density VLSI ECL technology was used and a new liquid cooling system was...

 series was announced in 1988; it also had a new design, replacing the 16-gate ECL gate array
Gate array
A gate array or uncommitted logic array is an approach to the design and manufacture of application-specific integrated circuits...

s with a more compact VLSI gate array with larger circuit boards. It was a major improvement of the X-MP supporting up to eight processors.

In popular culture

  • The parallel-processor nature of the X-MP and its ability to solve multi-variate simultaneous equations rapidly receives honourable mention in Tom Clancy
    Tom Clancy
    Thomas Leo "Tom" Clancy, Jr. is an American author, best known for his technically detailed espionage, military science, and techno thriller storylines set during and in the aftermath of the Cold War, along with video games on which he did not work, but which bear his name for licensing and...

    's novel, The Hunt for Red October
    The Hunt for Red October
    The Hunt for Red October is a 1984 novel by Tom Clancy. The story follows the intertwined adventures of Soviet submarine captain Marko Aleksandrovich Ramius and CIA analyst Jack Ryan.The novel was originally published by the U.S...

    , when 'Skip' Tyler uses the USAP's
    United States Air Force
    The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

     X-MP machine to work out the performance and sonic characteristics of the October for Jack Ryan
    Jack Ryan
    Jack Ryan may refer to:*Jack Ryan , a fictional character in a series of novels by Tom Clancy*Jack Ryan , former candidate for United States Senator from Illinois and ex-husband of actress Jeri Ryan...

     on behalf of the CIA in return for both profit and the chance to evaluate the vessel should it be successfully gained either temporarily or better yet permanently.
  • The film Tron
    Tron
    -Film:*Tron , a franchise that began in 1982 with the Walt Disney Pictures film Tron** Tron , a 1982 science fiction film by Disney, starring Jeff Bridges, Bruce Boxleitner, Cindy Morgan, Dan Shor and David Warner...

    , a Cray X-MP can be briefly seen in the foreground in the scene with Flynn & Lori en-route to her work station. Also the Cray X-MP is cited in the ending credits of the film as "Supercomputer".
  • The film The Last Starfighter
    The Last Starfighter
    The Last Starfighter is a 1984 science fiction adventure film directed by Nick Castle. The film tells the story of Alex Rogan , an average teenage boy recruited by an alien defense force to fight in an interstellar war. It also featured Dan O'Herlihy, Catherine Mary Stewart, Robert Preston, Norman...

    depended heavily on high polygon count (for the time) models with complex lighting effects, the rendering of which was made possible by the use of the X-MP.
  • In Michael Crichton
    Michael Crichton
    John Michael Crichton , best known as Michael Crichton, was an American best-selling author, producer, director, and screenwriter, best known for his work in the science fiction, medical fiction, and thriller genres. His books have sold over 200 million copies worldwide, and many have been adapted...

    's novel Jurassic Park, three Cray X-MPs provide the park's computing power.
  • In Jurassic Park: Trespasser
    Jurassic Park: Trespasser
    Jurassic Park: Trespasser is a video game released in 1998 for Microsoft Windows after much hype and anticipation. The player assumes the role of Anne, the sole survivor of a plane crash on InGen's "Site B" one year after the events of The Lost World: Jurassic Park...

    , a Cray X-MP is featured as the supercomputer supporting Site B.
  • In M. Ann Jacoby's novel Life after Genius, the main character uses the X-MP at Bell Labs
    Bell Labs
    Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...

     in New Jersey to calculate 1.5 billion zeros of the Riemann zeta-function.
  • The Cray X-MP was used for one of the first Pixar short films, "The Adventures of André and Wally B.
    The Adventures of André and Wally B.
    The Adventures of André and Wally B. is an animated short made in 1984 by The Graphics Group , which was later spun out as a startup company called Pixar...

    ", in 1984. Special thanks is given to Cray Research in the short's credits for use of the machine.

Further reading

  • Keith Robbins and S. Robbins (1989) Lecture Notes in Computer Science: The Cray X-MP/Model 24 Springer ISBN 3-540-97089-4
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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