The Cray X-MP was a supercomputer designed, built and sold by Cray Research. It was announced in 1982 as the "cleaned up" successor to the 1975 Cray-1, and was the world's fastest computer from 1983 to 1985 with a quad-processor system performance of 800 MFLOPS. 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 vector processor, the first such computer from Cray Research. It housed up to four CPUs in a mainframe that was nearly identical in outside appearance to the Cray-1.

The X-MP CPU had a faster 9.5 nanosecond clock cycle (105 MHz), compared to 12.5 ns for the Cray-1A. It was built from bipolar gate-array integrated circuits containing 16 emitter-coupled logic (ECL) gates 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 only one read/write port) and improved chaining support. Each CPU had a theoretical peak performance of 200 MFLOPS.

The X-MP initially supported 2 million 64-bit words (16 MB) of main memory in 16 banks, respectively. The main memory was built from 4 Kbit bipolar SRAM ICs. CMOS memory versions of the Cray-1M were renamed Cray X-MP/1s. This configuration was first used for Cray Research's UNIX port.

In 1984, improved models of the X-MP were announced, consisting of one, two, and four-processor systems with 4 and 8 million word configurations. The top-end system was the X-MP/48, which contained four CPUs with a theoretical peak system performance of over 800 MFLOPS and 8 million words of memory.

For magnetic tape I/O, the system could interface with IBM 3420 and 3480 tape units directly without a lot of CPU processing.

Successors

The Cray-2, a completely new design, was introduced in 1985. A very different compact four-processor design with from 64&nbsp;MW (megaword) to 512&nbsp;MW (512&nbsp;MB to 4&nbsp;GB) of main memory, it was specified to 500&nbsp;MFLOPS but was slower than the X-MP on certain calculations due to its high memory latency<!--Do not link to "RAM latency", which pertains to the latency of SDRAM, which the CRAY-2 did not use-->.

The Cray Y-MP upgrade of the X-MP series was announced in 1988; it also had a new design, replacing the 16-gate ECL gate arrays 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.

Usage

  • The short film The Adventures of André & Wally B., released in 1984 by The Graphics Group, a then-Lucasfilm subsidiary which would later become Pixar, used an X-MP/48 for much of its rendering. Special thanks is given to Cray Research in the short's credits for use of the machine.
  • The 1984 film The Last Starfighter 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.
  • The animation for the 1986 Marvel Productions logo, which featured an animated silver-colored Spider-Man, was rendered using this supercomputer.
  • Mick Jagger's single version of "Hard Woman" extensively utilised the X-MP for rendering its music video animation.

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Image:EPFL CRAY-I 2.jpg|Control panel of the CRAY X-MP/48

Image:EPFL CRAY-I 3.jpg|Logic boards of the CRAY X-MP/48

Image:EPFL CRAY-I 4.jpg|Cooling system of the CRAY X-MP/48

Image:BSC-CRAY-X-MP-EA-A.JPG|CRAY X-MP/24 at Barcelona Supercomputing Center

Image:BSC-CRAY-X-MP-EA-B.JPG|CRAY X-MP/24 at Barcelona Supercomputing Center

</gallery>

References

Further reading

  • Keith Robbins and S. Robbins (1989) Lecture Notes in Computer Science: The Cray X-MP/Model 24 Springer