Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site well.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!qantel!ptsfa!well!rchrd From: rchrd@well.UUCP (rchrd = Richard Friedman) Newsgroups: net.arch Subject: Alliant's FX/1 & FX/8 Super-minis: brief summary Message-ID: <203@well.UUCP> Date: Thu, 26-Sep-85 15:23:27 EDT Article-I.D.: well.203 Posted: Thu Sep 26 15:23:27 1985 Date-Received: Sun, 29-Sep-85 06:06:01 EDT Organization: Whole Earth Lectronic Link, Sausalito, CA Lines: 90 Keywords: Alliant Supermini vector parallel processing Here is a brief note about the ALLIANT FX/8 multiple processor system that you have all been asking about. This is just a summary for the purposes of distribution over the network. For more detailed information, contact Alliant Computer Systems, 42 Nagog Park, Acton, Mass. 01720 (617-263-9110) Alliant has announced two very interesting vector processors: the FX/1 and the FX/8. The FX/1 is a single cpu super-mini that stands desk high and can deliver 11 megaflops peak vector performance. The FX/8 is a 1 to 8 (field upgradeable) cpu system with 94 megaflops peak vector and 35 mips scalar. Both systems are completely compatible and run CONCENTRIX(tm), their version of 4.2BSD UNIX. The FX/1 consists of a single computational element (CE) and one or two interactive processors (IPs), operating in parallel and sharing the same UNIX kernel. The CE is a true vector processor, with 32-bit single precision and 64-bit double precision floating point, 8 32-element 64-bit vector registers, 16kb instruction cache, and additional hardware for concurrency control (for the FX/8). The system supports 2 gigabytes of virtual memory per process, which is served thru a 32 kb cache of 85 ns memory that can access physical memory at 94.1 mb/sec. Physical memory is one or two 8 mb memory modules. The FX/1 is intended to fit into an office environment and is no larger than (say) a SUN workstation (28.5" x 13.5"). It supports TCP/IP Ethernet and is completely compatible with the FX/8. The FX/8 can support from 1 to 8 CE's (computational elements), which are treated as a single resource by the operating system and can be unleashed to work in parallel on a single program. In addition, up to 11 interactive processors (IPs) can be installed, as well as up to 64 megabytes of physical memory in 8mb increments. The most interesting thing about the FX/8 is that the system is not only a vector machine, but it is also parallel processor! This means that programs may run in any of four execution modes: purely scalar, purely vector, scalar concurrent (distributed across processors), or vector concurrent (running vector mode across processors). Alliant has published the following performance rates: Peak Performance Single CE 8 CE Complex ------------------------------------------- scalar | 4.45 mips | 35.6 mips | - - - - - - - - - - - - - - - - - - - - - vector | 11.8 mflops | 94.9 mflops | ------------------------------------------- Concurrency, Alliant's term for parallel processing or multi/micro-tasking, is handled by a close co-operation between the FORTRAN compiler and the hardware. The compiler is a complete FORTRAN-77 that includes extensions for vector processing based on the proposed FORTRAN-8X standards. The compiler optimizes both scalar and vector code, and generates hardware instructions to initiate and synchronize parallel processing of a loop across processors. (On other systems like the CRAY-XMP with up to 4 processors, this sort of "multi-tasking" must be done explicitly by the program, using library calls). The overhead involved with initiating and synchronizing tasks is very low, on the order of a few clock cycles. This means that it is very reasonable to distribute each pass thru an outer DO loop across processors. The compiler recognizes such loops and does it all. No explicit code modifications are required except possibly adding an in-line compiler directive to enable concurrency. Indeed, a very interesting machine! I understand that they are now shipping systems and a number have already been installed. No word yet on response from the users. Oh yes... cost? Don't quote me, but I believe the fully outfitted, 8 CE 11 IP FX/8 is around $900K and a minimal FX/1 is in the area of $120K. I'll be back with more information as soon as I can get it. -- [rchrd] = Richard Friedman Pacific-Sierra Research, 2855 Telegraph #415 Berkeley, CA 94705 (415) 540 5216 UUCP: {dual,hplabs,ptsfa,apple}!well!rchrd Brought to you by Super Global Mega Corp .com