The Cray EL90 series was an air-cooled 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...

 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...

 first sold by Cray Research in 1993. The EL90 series evolved from the Cray Y-MP EL 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...

, and is compatible with Y-MP software, running the same 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...

. The range comprised three models:

• EL92, with up to two processors and 64 megawords (512 MB) of DRAM
  Dram
  Dram or DRAM may refer to:As a unit of measure:* Dram , an imperial unit of mass and volume* Armenian dram, a monetary unit* Dirham, a unit of currency in several Arab nationsOther uses:...
  
   in a deskside chassis: dimensions 42×23.5×26 inches or 1050×600×670 mm (height × width × depth) and 380 lb/172 kg in weight.
• EL94, with up to four processors and 64 megawords (512 MB) of DRAM, in the same cabinet as the EL92.
• EL98, a revised Y-MP EL with up to eight processors and 256 megawords (2 GB) of DRAM in a Y-MP EL-style cabinet (62×50×32 inches or 2010×1270×810 mm, 1400 lb/635 kg in weight).

The EL90 series Input/Output Subsystem (IOS) was based around the 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,...

 and a Heurikon HK68 Motorola 68000

Motorola 68000

The Motorola 68000 is a 16/32-bit CISC microprocessor core designed and marketed by Freescale Semiconductor...

-based processor board (or IOP). The IOP also provided the system's serial console. All EL90 models could be powered from regular mains power.

The EL90 series was superseded by the Cray J90

Cray J90

The Cray J90 series was an air-cooled vector processor supercomputer first sold by Cray Research in 1994. The J90 evolved from the Cray Y-MP EL minisupercomputer, and is compatible with Y-MP software, running the same UNICOS operating system. The J90 supported up to 32 CMOS processors with a 10 ns...

series.