G5 Processor upgrade for G4s?

Discussion in 'Macintosh Computers' started by leekohler, Jan 21, 2005.

  1. macrumors G5


    Dec 22, 2004
    Chicago, Illinois
    Does anyone know if Sonnet (or anyone else) will ever make a G5 processor upgrade for G4s? It seems to me that if they were, they would have done so by now. Is it a 32/64-bit issue or maybe a bus speed issue?
  2. Moderator emeritus


    Jul 24, 2002
    This was discussed to death when the G5 was announced. The bus is a major sticking point (not just speed, it talks a whole different language between the CPU and the northbridge). Also the memory bandwidth of a G4 (which is limited by the G4 north bridge) would really slow down a G5 chip.

    Basically it's probably not worth it. I'd hold out for a dual-core G4 upgrade somtime in 2006 (maybe even a dual dual-core upgrade?)
  3. macrumors 65816


    Feb 18, 2003
    I am no tech genius, but there would seem to be a basic motherboard-design incompatability I would imagine.
  4. thread starter macrumors G5


    Dec 22, 2004
    Chicago, Illinois
    Well-Sonnet already makes a dual processor G4 upgrade. It's pricey though-about $600 I believe. I'd buy a Mac Mini before I'd do that. I was just asking because I need to upgrade my Sawtooth desktop and didn't want to get another G4 processor if a G5 might be a possibility. Thanks-you guys answered my question.
  5. macrumors G4

    Lord Blackadder

    May 7, 2004
    Sod off
    Too bad I wasn't around, I've wondered the same thing myself. I'll have to go search for the thread...

    To the original poster:

    Beyond technical issues that I don' understand, I think a G5 upgrade is unlikely because the G4 is still a living design offering competitive performance. The G5 doesn't offer enough inherent advantage in the chip alone to make useful on a G4 motherboard, just higher clock really. can you say strangled by the bus?

    What you MAY see at some point (besides higher and higher clocked G4s) are dual-core or twin dual-core G4(2x G4s with dual cores - a tongue twister) upgrade solutions. And honestly, those will be overkill for the Powermac G4's architecture. Its' like putting a 500MHz G3 in a Powermac 6100: you can buy the kit, but you're really wasting the G3 becuse the mobo architecture is too old.
  6. macrumors G5

    Sun Baked

    May 19, 2002
    You might as we bite the bullet and wire an IBM PPC970 Blade into a PCI slot, much easier.

    The G5 requires both the CPU and the Memory controller, along with a small processor or chip -- just to initialize. You almost have a complete computer (without i/o) at that point.

    And you can't plug that into a 60x FSB.

    It would end up being a co-processor card, or something with an HT to 60x bridge chip.

    Almost like buying a z06 vette and updating the computer to limit in it Pontiac Grand Am performance.

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