Editing Cray Y-MP

{{short description|Supercomputer by Cray Research}}
{{More citations needed|date=September 2020}}
The '''Cray Y-MP''' was a [[supercomputer]] sold by [[Cray|Cray Research]] from 1988, and the successor to the company's [[Cray X-MP|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 [[emitter-coupled logic|ECL]] technology was used and a new liquid-cooling system was devised. The Y-MP ran the Cray [[UNICOS]] [[operating system]].

The Y-MP could be equipped with two, four or eight [[vector processor]]s, with two functional units each and a clock cycle time of 6 ns (167&nbsp;MHz). Peak performance was thus 333 [[megaflops]] per processor. Main memory comprised 256, 512, or 1024 MB of [[static RAM|SRAM]]. <ref>{{cite web  |title=The CRAY Y-MP Series of Computer Systems | url=https://cray-history.net/wp-content/uploads/2021/08/Y-MP8D_red_redux.pdf | page=10}}</ref> (Memory was measured and allocated in 64 bit words, and offered in 32, 64, or 128 MWords).

[[Image:Cray Y-MP GSFC.jpg|thumb|Cray Y-MP Model D at [[NASA]] Center for Computational Sciences, [[GSFC]]]]

The original Y-MP (otherwise known as the '''Y-MP Model D''') was housed in a chassis similar to the horseshoe-shaped X-MP, but with an extra rectangular cabinet added in the middle (containing the CPU boards), thus forming a "Y" shape in plan view. The system could be configured with one or two ''Model D'' IOSs (Input/Output Subsystems) and an optional Solid State Disk (SSD) of 256 MB to 4GB capacity. The Y-MP had a measured GFLOPS of 2.144 and a peak GFLOPS of 2.667 in both 1988 and 1989.<ref name=Linpack>{{cite web | url = http://www.netlib.org/utk/people/JackDongarra/faq-linpack.html#_Toc27885750 | title = Frequently Asked Questions on the Linpack Benchmark and Top500 | accessdate = 2014-01-14 | first = Jack | last = Dongarra | year = 2007|publisher=Netlib}}</ref>

The Model D Y-MP was superseded in 1990 by the '''Y-MP Model E''', which replaced IOS Model D with IOS ''Model E'', providing twice the I/O throughput. The Y-shaped chassis was dropped in favor of one or two rectangular cabinets (each with a separate connected cabinet containing the liquid-cooling system), depending on configuration. Maximum RAM was increased to 2 GB and up to eight IOSs were possible. Model E variants included the '''Y-MP&nbsp;2E''', '''Y-MP&nbsp;4E''', '''Y-MP&nbsp;8E''' and '''Y-MP&nbsp;8I''', the latter being a single-cabinet (''I'' for ''Integrated'') version of the two-cabinet 8E. The 2E and 4E were later available with optional secondary air cooling.

[[Image:Cray YMP M90 Ziegler 3.jpg|thumb|Cray Y-MP M90 (Ziegler) at the US [[National Cryptologic Museum]]]]

The '''Y-MP M90''' was a large-memory variant of the Y-MP Model E introduced in 1992. This replaced the SRAM of the Y-MP with up to 32 GB of slower, but physically smaller [[DRAM]] devices. The Y-MP M90 was also available in variants with up to two, four or eight processors ('''M92''', '''M94''' and '''M98''' respectively). Later, the model name was abbreviated to the Cray '''M90''' series.

[[File:Cray Y-MP EL at Computer Museum of America.jpg|thumb|left]]
The '''[[Cray C90|Y-MP C90]]''' series is described separately.

[[Image:Processor board cray-1 hg.jpg|thumb|Cray Y-MP processor board]]

== Y-MP EL ==
In 1992, Cray launched the cheaper '''Y-MP EL''' (''Entry Level'') model. This was a reimplementation of the Y-MP architecture in [[CMOS]] technology, based on the S-2 design acquired by Cray from [[Supertek Computers]] in 1990. The EL was an air-cooled system with a completely different [[VMEbus]]-based IOS. EL configurations with up to four processors (each with a peak performance of 133 megaflops) and 32 MB to 1 GB of [[DRAM]] were available.  The Y-MP EL was later developed into the Cray '''[[Cray EL90|EL90]]''' series ('''EL92''', '''EL94''' and '''EL98'''). [[File:National Cryptologic Museum Cray YMP M90 Board.jpg|left|thumb|Y-MP M90 board at the [[National Cryptologic Museum]]]]
The Y-MP EL came in a cabinet much smaller than the traditional room-filling Cray 2010×1270×810&nbsp;mm (height × width × depth) and 635&nbsp;kg in weight&mdash;and could be powered from regular mains power.
== In popular culture ==
In the 1992 film ''[[Sneakers (1992 film)|Sneakers]]'', whose story is centered around extremely high-level [[cryptography]], two lead characters have an important discussion while sitting on a Cray Y-MP.

In an episode of the television dramedy ''[[Northern Exposure]]'' titled "Nothing's Perfect", 
a character expresses her excitement at having finally gained access to a "CRAY Y-MP3" supercomputer.

== References ==
{{reflist}}
* Arthur Trew and Greg Wilson (eds.) (1991). ''Past, Present, Parallel: A Survey of Available Parallel Computing Systems''. New York: Springer-Verlag. {{ISBN|0-387-19664-1}}.

== External links ==
*[http://0x07bell.net/WWWMASTER/CrayWWWStuff/Cfaqp1.html Fred Gannett's Cray FAQ, Part 1]
*[https://web.archive.org/web/20131205182056/http://www.cray-cyber.org/systems/yel.php Working online Cray Y-MP EL in Cray-Cyber museum]

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 | title = [[LINPACK|World's most powerful supercomputer]]
 | years = 1988–1989
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{{Cray computers}}

[[Category:Computer-related introductions in 1988]]
[[Category:Cray products|Ymp]]
[[Category:Vector supercomputers]]
[[Category:64-bit computers]]