The Cray APP (''Attached Parallel Processor'') was a

parallel computer Parallel computing is a type of computation in which many calculations or processes are carried out simultaneously. Large problems can often be divided into smaller ones, which can then be solved at the same time. There are several different for ...

sold by

Cray Research Cray Inc., a subsidiary of Hewlett Packard Enterprise, is an American supercomputer manufacturer headquartered in Seattle, Washington. It also manufactures systems for data storage and analytics. Several Cray supercomputer systems are listed i ...

from 1992 onwards. It was based on the

Intel i860 The Intel i860 (also known as 80860) is a RISC microprocessor design introduced by Intel in 1989. It is one of Intel's first attempts at an entirely new, high-end instruction set architecture since the failed Intel iAPX 432 from the beginning of ...

microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...

and could be configured with up to 84 processors. The design was based on "computational nodes" of 12 processors interconnected by a shared bus, with multiple nodes connected to each other, memory and I/O nodes via an 8×8

crossbar switch In electronics and telecommunications, a crossbar switch (cross-point switch, matrix switch) is a collection of switches arranged in a matrix configuration. A crossbar switch has multiple input and output lines that form a crossed pattern of int ...

. The APP was marketed as a "matrix co-processor" system and required a

SPARC SPARC (Scalable Processor Architecture) is a reduced instruction set computer (RISC) instruction set architecture originally developed by Sun Microsystems. Its design was strongly influenced by the experimental Berkeley RISC system developed ...

-based host system to operate, such as the

Cray S-MP The Cray S-MP was a multiprocessor server computer sold by Cray Research from 1992 to 1993. It was based on the Sun SPARC microprocessor architecture and could be configured with up to eight 66 MHz BIT B5000 processors. Optionally, a Cray APP matr ...

. Connection to the host system was via

VMEbus VMEbus (Versa Module Europa or Versa Module Eurocard bus) 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. I ...

or HiPPI. A fully configured APP had a peak performance of 6.7 (single-precision)

gigaflops In computing, floating point operations per second (FLOPS, flops or flop/s) is a measure of computer performance, useful in fields of scientific computations that require floating-point calculations. For such cases, it is a more accurate meas ...

. The APP was originally designed by

FPS Computing Floating Point Systems, Inc. (FPS), was a Beaverton, Oregon vendor of attached array processors and minisupercomputers. The company was founded in 1970 by former Tektronix engineer Norm Winningstad, with partners Tom Prince, Frank Bouton and Robe ...

as the FPS MCP-784. FPS were acquired by Cray Research in 1991, becoming Cray Research Superservers Inc., and the MCP-784 was relaunched by Cray in 1992 as the APP.

References

Cray Attached Parallel Processor (APP) brief, SunFLASH Vol 58 #2, October 1993.
{{Cray computers App Supercomputers