Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!ucla-cs!ucla-seas!boole!plinio From: plinio@boole.seas.ucla.edu (Plinio Barbeito/;093091;allsites) Newsgroups: comp.sys.atari.st Subject: Re: TT upgrades Keywords: 88000 Message-ID: <1910@lee.SEAS.UCLA.EDU> Date: 10 Feb 91 12:09:54 GMT References: <1991Feb8.010109.396@jato.jpl.nasa.gov> <1991Feb8.064335.26267@cs.ucla.edu> <1991Feb8.204957.10770@jato.jpl.nasa.gov> Sender: news@SEAS.UCLA.EDU Distribution: na Organization: SEASnet, University of California, Los Angeles Lines: 93 In article <1991Feb8.204957.10770@jato.jpl.nasa.gov> vsnyder@jato.Jpl.Nasa.Gov (Van Snyder) writes: >1. Speed. I don't count how many instructions are executed per second. I ... > the same clock rate, the 88000 gets done twice as fast as the 68040. Running what software? Not existing ST software. To run ST software without modification requires that the 88000 system be able emulate 680x0 instructions, or that all of the developers port their software to it (a dubious proposition 8-P ). Assuming an emulator was written, you'd need to crank much more than twice the dhrystones to keep up with the 040. For present 68000 machine owners, the 68040 is not an "obsolete" upgrade path in terms of speed. It will run their existing software much faster than any processor that will fit in their case (see, this excludes the Cray :) ). What software did you have in mind? >2. REAL customer: A stable company with a good reputation that buys several ... You don't need real customers if you have real volume; the kind of volume intel gets from the jillion little clone companies buying 80286's. As long as the new 486 runs DOS programs, intel doesn't need one real customer to make money off of it. The same could be true of Motorola, if Mac clones (for example) became ubiquitous. As evidence of this, the success of Sun's SPARC technology is due in large part to the fact that Sun didn't keep it proprietary, actually encouraging third parties to produce it, assuring a large installed base, assuring a future demand for new and improved Sun workstations and software. >3. CAMMU means "Cache And Memory Management Unit", presently a separate chip. This seems a good way to design a fast system, even a system that is easy to implement into a final product, but it is not the way to make an economical personal computer, where you try to reduce the chip count as much as possible. Instead of buying one chip, you have to buy three. This is likely to cost more than buying one chip. See item 4 (PRICE?) below. >4. I know that 200 Mhz means 5 ns clock, and that a Y-MP has a 6+ ns clock. ... > a 68xxx will need 2-4 times as many transistors, and therefore ultimately > COST A LOT MORE.) As someone mentioned, the price of a memory system to support a 200MHz clock is prohibitive. A cheap processor with an expensive memory system and many expensive memory chips costs more than one expensive processor and a simple memory system and many cheap memory chips. Notice that the 68040 includes an FP and cache on-chip. That effectively reduces chip count and final system cost, if you were going to include the FP and cache anyway. If you weren't, you might be interested in the fact that Motorola plans to release a low cost version of the 68040 this year ...I think it's called the 68EC040. No FP, smaller cache, fewer transistors: lower price. Just what the doctor ordered for upgrade boards. Of course, right now it's just as available as the 200MHz 88K :-). ... > I don't think the > price of 88xxx chips will be FOREVER greater than the price of 68xxx > chips, if for no other reason than the 88xxx has fewer transistors! Another way to look at it is that they will forever cost about the same and the 68xxx will be slower. But that does not mean people will deem it obsolete in terms of their own needs. For most people's personal needs, a 68030 is not just adequate, it's ideal. Unlike the 68000, it has an on-chip cache (256 words of data, 256 words of instructions), so that even if it's driven up to 33MHz and used with slow (cheap) memory chips, it may not necessarily need a large external cache to give a reasonable speed improvement over 16 or 25MHz versions. Furthermore, a 16MHz 68030 is dirt cheap NOW. And if you could get a 50MHz 68030 at a similar price, you could have your cake and eat it too. For reference, my definition of 'obsolete': A product is obsolete if there is something better which can be used for the same purpose. That's why I think that if people can't use the alternative because it costs more than they are willing to pay, or if it isn't fit for the same purpose, then the original product is not obsolete. >vsnyder@jato.Jpl.Nasa.Gov >ames!elroy!jato!vsnyder >vsnyder@jato.uucp plini b -- ----- ---- --- -- ------ ---- --- -- - The proper place for the capslock key is not where the key 'control' used to be. plinio@seas.ucla.edu * Boelter 4442 lab: 206-1982, Boelter 3760: 825-7413