Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!elroy.jpl.nasa.gov!usc!ucla-cs!ucla-se!turing!plinio From: plinio@turing.seas.ucla.edu (Plinio Barbeito) Newsgroups: comp.arch Subject: Re: VISC - A way to speed up moto cisc mpu's? Message-ID: <2842@lee.SEAS.UCLA.EDU> Date: 23 May 91 03:15:14 GMT References: <1991May15.183328.22820@kithrup.COM> <13445@dog.ee.lbl.gov> <1991May23.210000.8152@kithrup.COM> Sender: news@SEAS.UCLA.EDU Organization: SEASnet, University of California, Los Angeles Lines: 55 In article <1991May23.210000.8152@kithrup.COM> sef@kithrup.COM (Sean Eric Fagan) writes: >In article <13445@dog.ee.lbl.gov> torek@elf.ee.lbl.gov (Chris Torek) writes: >>Why not just build a multiprocessor system with completely different >>processors? I.e., ship a system that contains, say, one 68040 and one >>or more 88x00s. There is no particular reason that the O/S cannot run >>the proper binary on the proper CPU automatically. Interesting... this could lead to a more intelligent distributed process server. One that not only takes which CPU the least loaded into consideration for exec'ing new processes, but also how fast a given code will run on that system or CPU. For example, in such a system, the O/S could use the 040 to move blocks of memory around and floating point, the 486 to do the strcmp's, the RIOS to do the published Dhrystone benchmark, :-) and the i860 to provide an excuse for the frequent down-time and delivery delays :-) :-) (I went a bit overboard with that one...) Maybe not just binaries, but different library functions could be assigned to different processors. I can't help but think that there would be *something* a CISC processor would be consistently better at over its RISC contemporary. Based on previous experience in this group, Somebody Has Already Thought Of This. If it's true that SHATOT, then please share it with us. >Because then you wouldn't get any speedup on your old programs. I guess. >Historically, such ventures have not done too well. (Anyone remember the >machine, many years ago, that had a 68k, a 6502, a Z80, and possibly one or >two other processors? Dimension, mayhap? Anyway, it failed.) Yes, but how many Apple II's (ages hence) didn't have a Z80 card so people could run CP/M? Also, Intel's 'vision of the future', as they have explained it, is that the i860 family is not intended to compete with or replace the 80x86 line for desktop systems, but that it will accompany (or so they would hope) most of them as a card to "speed up operations". Then again, maybe they don't really think this would fly and are just using it as a ploy to calm investors paranoid of self-competition hurting immediate maximal profits. Possibly, the strategy of combining different processors would meet more consistent success if each processor was *needed* there to run a given operating system (or other suitable, presently existing investment in a body of software), and if the parts were cheap enough, and the signals compatible enough (the latter of which is why I think Chris must have mentioned the 040 together with the 88k's). A nice example of this might be a mac server, with the 040 running Mac-os and the other processors running an unhindered version of Unix, serving files out, etc. plin -- ----- ---- --- -- ------ ---- --- -- - - - plinio@seas.ucla.edu Para-noia will destroy-yaaaaa...