G5 1.8 upgrade to G5 2.3

Discussion in 'PowerPC Macs' started by iceclimber1967, Feb 26, 2008.

  1. iceclimber1967 macrumors newbie

    Feb 26, 2008
    Hello all!! I just bought a G5 mac tower with dual 1.8s. I also purchased a pair of 2.3s and the power supply from dual 2.3 as well. Can I just drop the new processors into the slots and have them work?? Is there anything I need to do to facilitate this upgrade?? Any help would be appreciated!!

  2. aibo macrumors 6502

    Jan 17, 2008
    Southern California
    You need the 2.3 motherboard... something about the G5 firmware locking you in. The bus speed is not adjustable, therefore the CPUs won't run at 2.3GHz.

    I recall someone trying to do this, but it threw off thermal calibration and put his fans at a constant full-blast, and the CPU speed wasn't what he hoped.
  3. iceclimber1967 thread starter macrumors newbie

    Feb 26, 2008
  4. Lord Zedd macrumors 6502a

    Lord Zedd

    Oct 24, 2007
    Denver, Colorado
    He is right, this isn't like the old G4 where you could throw in a new CPU card and everything would be fine and dandy. The G5 CPU is tied to the motherboard now. Even if you remove the CPUs and don't put them back the same (You put CPU1 in slot 2 and CPU2 in slot 1 for example or replace one of the CPUs with a different one) you must use an Apple Service Diagnostic CD to recalibrate the thermal controls.

    There will likely never be a CPU upgrade for the G5, you're stuck with swapping a bunch of parts between different chassis.

    Basically, if you want a 2.3 you're better off selling your 1.8 and buying a complete 2.3 than swapping parts.

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