Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!usc!samsung!uunet!snorkelwacker.mit.edu!ai-lab!raisin-scone!lethin From: lethin@raisin-scone.ai.mit.edu (Richard A. Lethin) Newsgroups: comp.arch Subject: Re: massive parallelism, was CDC 6600 and TI ASC Message-ID: <13834@life.ai.mit.edu> Date: 8 Mar 91 16:20:14 GMT References: <45252@ut-emx.uucp> <1991Mar7.215545.430@zoo.toronto.edu> Sender: news@ai.mit.edu Organization: MIT Artificial Intelligence Laboratory Lines: 15 In article lamson@el1.crd.ge.com (scott h lamson) writes: >Given this line of reasoning, how do you look at massive parallel ala >the connection machine? Should you think of the CM as a slow scalar >machine with a super fast very long vector processor? If so, will it >fail for the same reasons you give? One difference is vector units >take only 1 clock cycle for each additional operation, whereas CM's >take no extra clock cycles for each additional operation (until you >run out of processors). but this has nothing to do with the scalar >speed argument anyway. Another important advantage of a CM and a long vector machine is that the CM has more wires: more communication. While communication steps can be very costly, they don't need to pass through the bottleneck of a Central processing unit as they might when doing a scatter/gather on a vector machine.