Will 970 upgrade cards work with current G4's?

Discussion in 'Macintosh Computers' started by pepeleuepe, Apr 9, 2003.

  1. pepeleuepe macrumors 6502

    Oct 27, 2002
    Los Angeles, California
    I was wondering if someone, (hopefully me) purchased a new G4 tower today and the rumored PPC 970 comes out at the end of the year, will there be upgrade cards available to put a 970 processor on the G4 motherboard? This may be a stupid question because IBM makes one processor and Motorola makes the other, so the motherboads might not be compatible, but if this is a possibility it would make my buying decision much easier. Either way I'm going to buy a new Power Mac, I just want to know if I go with the Dual 1.25 instead of the 1.42, will I be able to upgrade to a faster (hopefully 970) processor at some point? Thanks :) .
  2. robbieduncan Moderator emeritus


    Jul 24, 2002
    Most likely no. And if there is a way of making it work it'll be really, really slow! The 970 is going to have a totally different FSB which is going to be clocked much faster than the current G4 FSB. The entire chip will be optimised towards this. So even if you could find a way to interface it to this it would basically suck. I imagine that it would be hard to get the 64 bit 970 to work on a 32 bit G4 motherboard (and yes although the 970 has a 32 bit full speed compatability mode it is still a 64 bit chip).
  3. barkmonster macrumors 68020


    Dec 3, 2001
    I imagine it would be something along the lines of the Zif Daughterboards available for pre G3 powermacs if 970 based upgrades are even possible.

    You'd need to have a chipset on the daughterboard to deal with that 800Mhz DDR FSB, something that can easily scale it down to 100, 133 or 167Mhz so it will work on all G4 motherboards.

    They'd probably have 2 versions of the daughter board in either single or dual CPU versions and then just install the 970 chips on the cards in various clockspeeds.

    A lot of the benefit of the chip would be lost due to bandwidth restrictions, a PPC970 would still be faster than a G4 of the same clockspeed but not enormously when it's still only getting 800Mb/s - 1.3Gb/s of bandwidth compared with the 6.4Gb/s it's designed for. It sounds like upgrades would be possible if cost doesn't make a daughterboard approach impractical. It certainly works out nicely on paper for the 1.2Ghz PPC970, with such a low powered chip, a dual PPC970 upgrade shouldn't require any more cooling in an older mac that a single 1.2Ghz G4 upgrade requires now.
  4. macmunch macrumors regular

    Jan 6, 2002

    You know how slow this Chip will be on this Architecture !

    Dont forgett he will also have Hyper Transport connections !
    And the Fast RAM (maybe DUAL Channel) to fit the Bus from the chip with data !

    So how you coul stick such a beast in a old G4 ???

    You would have an 970 with 1,2 which runs as one with 100 Mhz !
  5. Tim Flynn macrumors regular

    Jan 9, 2003
    Its not likely that a daughter card would be worth while.
    Replacing the motherboard would be the best option. Hopefully Apple will have a similar design between the 970 cases and the present G4 cases.
  6. Latino macrumors member

    Apr 4, 2003
    London, UK
    The problem will then be to get hold of a reasonably priced 970 motherboard (and possibly PSU). In my experience/research, it's just not worth building your own powermac, unless you know enough electronics to get it right first time, and build things like your own PSU convertor boards and the like

    A 970 in current powermacs as an upgrade card seems very unlikely. It might be possible, but not cost effective. Also, the bandwidth limitations of the current architecture would prove quite a bottleneck!

    I am also in the same boat. I need a new machine, but want a 970. In the end, I think I might get an iBook (when the new ones come out, soon I hope), and use it to bridge the gap from now until rev 2 970 powermac
  7. macphoria macrumors 6502a


    Nov 29, 2002
    I'm sure someone will come up with 970 upgrade card for G4 Power Mac. But as people here previously mentioned, though it maybe faster than G4 Power Mac, it will not be able to reach full potential of 970 processor because of various limitations posed by older hardare on the newer processor. If it is 970 and all of its glory you want, I really don't think you should think about upgrade, rather purchase of the whole new computer equipped with 970.
  8. Snowy_River macrumors 68030


    Jul 17, 2002
    Corvallis, OR
    I'd tend to concur with everything that's been said by other, so I won't reitterate it. However, I'd also say that, if you can afford to, I'd recommend waiting at least until WWDC. That's when we're rumored to be seeing new PMacs, and it's only a couple of months away. For the benefit that the 970 could potentially offer, I'd be very inclined to wait, if I were in your position.

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