The J–Machine (Jellybean-Machine) 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 f ...

MIT The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

Concurrent

VLSI Very large-scale integration (VLSI) is the process of creating an integrated circuit (IC) by combining millions or billions of MOS transistors onto a single chip. VLSI began in the 1970s when MOS integrated circuit (Metal Oxide Semiconductor) ...

Architecture group in conjunction with the

Intel Corporation Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 series ...

. The machine used "jellybean" parts—cheap and multitudinous commodity parts, each with a processor, memory, and a fast communication interface—and a novel network interface to implement

fine grained Granularity (also called graininess), the condition of existing in granules or grains, refers to the extent to which a material or system is composed of distinguishable pieces. It can either refer to the extent to which a larger entity is subd ...

parallel programs.

History

The J-machine project was started in 1988 based on work in

Bill Dally William James Dally (born August 17, 1960) is an American computer scientist and educator. Since 2021, he has been a member of the President’s Council of Advisors on Science and Technology (PCAST). Microelectronics He developed a number of ...

doctoral A doctorate (from Latin ''docere'', "to teach"), doctor's degree (from Latin ''doctor'', "teacher"), or doctoral degree is an academic degree awarded by universities and some other educational institutions, derived from the ancient formalism '' ...

work at

Caltech The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...

. The philosophy of the work was "processors are cheap and memory is expensive," the ''J'' in the project's title standing for

jellybean Jelly beans are small bean shaped sugar candies with soft candy shells and thick gel interiors (see gelatin and jelly). The confection is primarily made of sugar and sold in a wide variety of colors and flavors. History It has been clai ...

which are small cheap candies. In order to make use of large numbers of processors, the machine featured a novel network interface using

message passing In computer science, message passing is a technique for invoking behavior (i.e., running a program) on a computer. The invoking program sends a message to a process (which may be an actor or object) and relies on that process and its supporti ...

. This allowed a node to send a message to any other node within 2

microseconds A microsecond is a unit of time in the International System of Units (SI) equal to one millionth (0.000001 or 10−6 or ) of a second. Its symbol is μs, sometimes simplified to us when Unicode is not available. A microsecond is equal to 100 ...

. Three 1024-node J-machine systems have been built and are kept at

and

Argonne National Laboratory Argonne National Laboratory is a science and engineering research national laboratory operated by UChicago Argonne LLC for the United States Department of Energy. The facility is located in Lemont, Illinois, outside of Chicago, and is the lar ...

External links

The Jellybean Machine

Notes

Massively parallel computers {{Compu-hardware-stub