Beige G3 Desktop - CPU Upgrade

Discussion in 'PowerPC Macs' started by LarsG5, Jan 21, 2017.

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  1. LarsG5, Jan 21, 2017
    Last edited: Jan 21, 2017

    LarsG5 macrumors member

    LarsG5

    Joined:
    Aug 10, 2016
    #1
    Hello,
    I would like to upgrade the CPU of my Beige 266MHz G3, but I need some info about how to do it.
    I have a spare 300MHz CPU taken out of B&W G3 (although I don't have any clue if it actually works) and I'd like to install it in my Beige G3.
    I've recently made some research and I've read, that it is possible, despite the difference in FSB between those 2 models. I've also stumbled across this article: http://www.wmld.com/tech/jumperchart2.html, but, to be honest, I'm not sure if I got it right.
    What should I do to make the B&W CPU work on my Beige? Simply adjust the jumper on Beige's motherboard to change its multiplier from 4x to 4,5x?

    And most important thing - is this safe to do? What are the consequences? Do I need to change the power supply?

    I'll be very grateful for any info.

    Wish you all a great weekend.
     
  2. bunnspecial macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #2
    I have a beige running a 400mhz B&W CPU at 433mhz.

    This is a straightforward swap and shouldn't give you any problems. As the stock computer has a jumper "block", you'll need to get some SCSI-sized jumpers to set it individually. As you said, set it to 4.5x to get it to run at the correct frequency.

    If you really want a good but affordable CPU upgrade, find a Sonnet Encore G4 in the 400-500mhz range. These work fine with the stock heatsink and don't require you to mess with the jumpers(they are plug and play). Sonnet made faster G4s that fit these computers(I have a 1ghz in a minitower), but they are $$$.
     
  3. LarsG5 thread starter macrumors member

    LarsG5

    Joined:
    Aug 10, 2016
    #3
    Thanks for the answer!
    So... I can feel safe that the power supply won't explode or anything? :D
    Well... That's awesome!

    To be clear: I don't need to mess with PCI bus nor FSB, only with the CPU clock jumper section?
     
  4. bunnspecial macrumors 603

    bunnspecial

    Joined:
    May 3, 2014
    Location:
    Kentucky
    #4
    Correct-ONLY change the multiplier. Changing the bus speed settings can result in unintended consequences.
     
  5. LarsG5 thread starter macrumors member

    LarsG5

    Joined:
    Aug 10, 2016

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