Cray X-MP
The Cray X-MP was a supercomputer that was developed, built, and sold by Cray Research . It was the company's first parallel vector processor-based computer and in 1982 it was the successor to the Cray-1, which appeared in 1976 . From 1983 to 1985 it was the fastest computer in the world.
description
The X-MP continued the " horseshoe " principle of the earlier computers and looked almost like its predecessor from the outside. The processors were clocked at 100 MHz (10 nanosecond cycle duration), which was 25% faster than the Cray-1A and enabled a theoretical computing power of 200 megaflops per processor, i.e. a total output of 800 megaflops for the four-processor machine. The processors also had improved support for chained computation, parallel arithmetic pipelines, and access to shared memory over multiple pipes.
The proprietary Cray Operating System (COS) initially ran on this hardware , whereby Unicos (a UNIX System V descendant) could be run via a guest operating system option. UniCOS became the main operating system from 1984.
Furnishing
The X-MP was sold with one, two or four processors and one to sixteen megawords (8–128 MB ) of main memory. While the memory was initially limited to 16 megawords by a 24-bit address register, the later XMP / EA memory architecture expanded the usable memory to theoretically two gigabytes. However, the largest memory produced in practice was only 64 megabytes. The XMP / EA had a clock speed of 8.5 ns, which enabled a theoretical maximum computing power of 942 megaflops. In 1982, an X-MP / 48 without mass storage cost around $ 15 million.
successor
In 1985 the Cray-2 was presented with a completely new architecture. With a compact four-processor architecture that differs significantly from the X-MP and 512 MB to 4 GB of main memory, it should achieve up to 488 megaflops according to its specification, but was slower than the X-MP in some calculations because its memory was very large Had latency times (in 1986 a standardized LINPACK test of an X-MP / 48 measured a speed of 713 megaflops).
The successor series of the X-MP, the Cray Y-MP , was sold from 1988; it was an evolutionary further development of the X-MP with a capacity of up to sixteen processors not much changed in architecture.
literature
- Kay A. Robbins, Steven Robbins: The Cray X-MP, model 24 - a case study in pipelined architecture and vector processing. Springer, Berlin 1989, ISBN 0-387-97089-4
