bwong@ihwpt.ATT.COM (bruce wong) (05/27/88)
First, a repeat of part of my second posting: Subject: General purpose commercial multiprocessor systems without shared- memory By general purpose multiprocessor system I mean that the machine looks like a uniprocessor machine to the user at the shell level and at the application programming level. The user is not concerned at all about processor allocation and application partitioning. This probably means that parallelism occurs at the process level. These are the commercial systems which fit the requirements: AT&T 3B4000 ELXSI NCR TOWER 32/800 Various Transputer machines As you will notice below, I don't have much information on the ELXSI. Is it still in business ? I also got mail about experimental systems. I have included some of those below. #-----------------------------------------------------------------------------# I assume that you, by now, have heard of the AT&T 3B4000 (though our Marketing people are doing a good job of keeping it a secret!). It is a multiprocessor (up to 14 adjunct processors in addition to the Master Processor) which looks from the outside (at the shell and application level) like a single UNIX machine. Each processor has the full set of SVR3.1.1 shared memory primitives, but a shared memory segment cannot (yet) be shared across processors. Hence, there is local shared memory (between processes running on the same processor) and no global shared memory (between processes running on different processors). Incidently, this restriction is consistent with the SVID, which identifies shared memory as a machine-dependent feature. In case you would like a closer look, the machine ihaxa at the IHCC is a 3B4000. Rich Strebendt [iwsl6|ihlpe|ihaxa]!res [cuuxf|cuuxg]!iw1res!res #-----------------------------------------------------------------------------# I believe that ELXSI use messages, and don't have shared memory. -- Don lindsay@k.gp.cs.cmu.edu CMU Computer Science #-----------------------------------------------------------------------------# The NCR TOWER 32/800 implements a loosely-coupled multiprocessor system with separate Application, File, Terminal, Communications and Ethernet processors that are connected by Multibus II. Each processor has its own private memory, although cross-processor memory accesses are also allowed. Further, the system may be configured with multiple Application processors that implement parallel processing in the method you describe -- that is, on the process level. No special application coding is needed to exploit the feature, and it is transparent to the shell and to users. Currently runs AT&T V.2.2. Steve Wingard ...!ucbvax!sdcsvax!ncr-sd!ncrcae!wingard NCR Corp., E&M-Columbia ...!decvax!mcnc!ncsu!ncrcae!wingard TOWER Muliprocessing Systems wingard@ncrcae.NCR.COM #-----------------------------------------------------------------------------# We have several customers who build, and market, non-sharded memory, general purpose multiprocessor computers, built with the (INMOS) transputer as the processing and communication element. Some such vendors are Meiko, THORN-EMI, Parsytech (not sure about the spelling),Topologix. I've left out Floating Point Systems because I feel that the T-series is a rather specialised computer (it consists of a number of interconnected vector processors). As one example of an installation of a non-shared memory multiprocessor computer, Edinburgh University (Scotland) have a large Meiko machine, with about 200 processors currently, which supports multi-users, networked access etc etc. (The processors are mainly IMS T800s, which mean that the whole system has a sustainable performance of somewhere in the 300-400 MFlop region!). The Edinburgh machine has been used for a wide range of application areas. There are plans (subject to raising the necessary funds) to expand this system to around a 1000 processors I believe. I hope this is of use, and I ought to appologise to any of our customers I have insulted by omitting them from this list. Roger Shepherd INMOS Ltd 1000 Aztec West Bristol BS12 4SQ, Great Britain ....!mcvax!euroies!shepherd #-----------------------------------------------------------------------------# Ah you mean automatic partitioning, etc. Well, I don't know of any turn key parallel systems, but if users are willing there are a host of near raw machines, mostly shared memory which have some neat features: Sequent, Encore, Flex, etc. But this does not constitute an endorsement. In the organization I just left, we have been approached by DEC on their M31 project (as were many other people) with parallel VMS (See COMPCON'88), two different IBM projects, and numerous startups. Remember a processor in hand is worth 1,000 in the simulator. Another gross generalization from --eugene miya, NASA Ames Research Center, eugene@aurora.arc.nasa.gov #-----------------------------------------------------------------------------# From: ihnp4!thumper!hammond (Rich A. Hammond) I know this isn't commercial, yet, but here at Bell Communications Research there are two multi-processor versions of UNIX using either Ethernet or a Ring to connect machines that appear to the user as a single machine without processor boundaries. Both support process migration between processors and handle signals, ... properly across mutliple processors. At least one version could become commercial strength with very little effort. Rich Hammond #-----------------------------------------------------------------------------# -- Bruce F. Wong 1A-111 312-416-5111 ATT Bell Laboratories ihnp4!ihwpt!bwong 200 Park Plaza Naperville, Ill 60566-7050