J–Machine
{{Short description|Parallel computer}}The J–Machine (Jellybean-Machine) was a parallel computer designed by the MIT Concurrent VLSI Architecture group in conjunction with the Intel Corporation. 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 parallel programs.{{Cite web | title = The J-Machine: A Retrospective | url = http://cva.stanford.edu/publications/1998/jm_retro.pdf | year = 1998 | first1 = William | last1 = Dally | authorlink = Bill Dally | first2 = Andrew | last2 = Chang | first3 = Andrew | last3 = Chien | first4 = Stuart | last4 = Fiske | first5 = Waldemar | last5 = Horwat | first6 = John | last6 = Keen | first7 = Richard | last7 = Lethin | first8 = Michael | last8 = Noakes | first9 = Peter | last9 = Nuth | accessdate = 2009-06-17 }}
History
The J-machine project was started in 1988 based on work in Bill Dally's doctoral work at Caltech.{{Cite web |title=J-Machine Project Page |url=http://web.mit.edu/sctv/OldFiles/old_sites/20030413045411/http://cva.stanford.edu/j-machine/cva_j_machine.html |access-date=2022-12-30 |website=web.mit.edu}}
The philosophy of the work was "processors are cheap and memory is expensive," the J in the project's title standing for jellybean 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.{{cite book | title = Principles and practices of interconnection networks | url = https://archive.org/details/principlespracti00dall_883 | url-access = limited | first1 = William J. | last1 = Dally | authorlink = Bill Dally | first2 = Brian | last2 = Towles | publisher = Morgan Kaufmann | year = 2004 | isbn = 0-12-200751-4 | pages =[https://archive.org/details/principlespracti00dall_883/page/n67 102]–109 }} This allowed a node to send a message to any other node within 2 microseconds.{{cite book | title = Parallel supercomputing in MIMD architectures | chapter = 12. The J-Machine: A fine-grain concurrent computer | last = Hord | first = R. Michael | publisher = CRC Press | year = 1993 | isbn = 0-8493-4417-4 | pages = 225–236}}
Three 1024-node J-machine systems have been built and are kept at MIT, Caltech and Argonne National Laboratory.{{cite web | url = http://cva.stanford.edu/projects/j-machine/ | title = The Jellybean Machine | publisher = CVA Group, Stanford University | accessdate = 2009-06-17 }}
External links
- [http://cva.stanford.edu/projects/j-machine/ The Jellybean Machine]