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G3 ZIF Upgrade with overclocked Systembus?
Posted by: avw on 2014-12-16 09:09:15 This question might be very specific, but perhaps somebody has tried this before? I own a PM G3/233 DT that I overclocked very sucessfully to 83 MHz systembus speed and 292MHz CPU speed. This machine is a lot faster when overclocked, and totally stable (I would have been the absolute hero in 1999 with this computer 😉 ). Especially the systembus seems to make a real difference. Now I got my hand on a Sonnet G3 1 GHz upgradecard. Inside the BW G3s this card is clocking down the systembus from 100MHz to 66. Now my question is if I can try to use this upgrade with the overclocked systembus inside my G3 DT? Or may I harm the machine? Or should it simply clock down the systembus again? Or may it perhaps work with the 83MHz?
Posted by: trag on 2014-12-16 09:16:53 You might wish to check some of the old articles at xlr8yourmac.com on clock chipping the Beige G3, but if I remember correctly, the bus speed on the Beige G3 is controlled by a jumper in a bank of jumpers and the settings on the ZIF have nothing to do with it. So, if you install the card in a Beige G3, you should get whatever bus speed you have set using the jumpers. The 1 GHz PPC750 (G3) supports a bus multiplier up to 20:1, so be careful what settings you choose. With an 83MHz bus speed, you could, in theory, end up with a 1600+ MHz G3 speed. Probably wouldn't damage anything, but won't do it any good either. I think that ZIF defaults to 10:1 when first booting though, so you should be okay.
Posted by: Macdrone on 2014-12-16 18:17:25 The G3 B&W has the same jumper, but different settings. I agree with the xlr8 Mac site. Most of this info is there.
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