The Cray XMS was a 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...

 minisupercomputer

Minisupercomputer

Minisupercomputers constituted a short-lived class of computers that emerged in the mid-1980s. As scientific computing using vector processors became more popular, the need for lower-cost systems that might be used at the departmental level instead of the corporate level created an opportunity for...

 sold by Cray Research from 1990 to 1991. The XMS was originally designed by Supertek Computers

Supertek Computers

Supertek Computers, Inc. was a computer company founded in Santa Clara, California in 1985 by Mike Fung, an ex-Hewlett-Packard project manager, with the aim of designing and selling low-cost minisupercomputers compatible with those from Cray Research....

 Inc. as the Supertek S-1, intended to be a low-cost air-cooled clone of the Cray X-MP

Cray X-MP

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 CMOS

CMOS

Complementary metal–oxide–semiconductor is a technology for constructing integrated circuits. CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits...

 re-implementation of the X-MP processor architecture, and a VMEbus

VMEbus

VMEbus is a computer bus standard, originally developed for the Motorola 68000 line of CPUs, but later widely used for many applications and standardized by the IEC as ANSI/IEEE 1014-1987. It is physically based on Eurocard sizes, mechanicals and connectors , but uses its own signalling system,...

-based Input/Output Subsystem (IOS). The XMS could run Cray's 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...

 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...

. Supertek were acquired by Cray Research in 1990, and the S-1 was rebadged XMS by Cray. Its processor had a 55 ns clock period (18.2 MHz clock frequency) and 16 megawords (128 MB) of memory.

The CRAY XMS system was the first CRI computer system to be supported by removable disk drives.

Serial 5011, on display, was used for marketing purposes in the Eastern Region. It traveled for over 80,000 miles during its short working life and appeared at many trade shows.

The XMS was a short-lived model, and was superseded by the Cray Y-MP EL, which was under development by Supertek (as the Supertek S-2 and briefly as the Cray YMS) at the time of the Cray acquisition.