Help w/OS on a 400 Mhz iMac G3


macrumors member
Original poster
Oct 19, 2004
Searcy, AR
I am working on an iMac G3 running at 400 Mhz. I have 10.2.8 intalled and running great. When i first took on upgrading this machine it said that it could not install os 10.3 because it needed a firmware upgrade. I am wondering if i could install 10.3 now that i have installed 10.2.8. (Did it upgrade drivers with that install)? I guess i am currious if there is a limit to the highest sytem you can run on a OS X capable system. The ram is at 320 so that is not a short-come. It also contains a 2x AGP with an ATI rage w/8MB of vram i believe. It is a surprisingly responsive machine as it is and i just am looking for some of the functionality that come with the .3 upgrade. Any advice or help?


macrumors regular
Feb 1, 2005
I have a graphite 400Mhz G3 iMac that is running OS 10.3.7. Relatively snappy and never crashes. I don't remember having to install any firmware when I went from 10.2.8 to 10.3. So I don't think it's a hardware issue 10.3.8 should work flawlessly on your machine.

Good Luck


macrumors regular
Sep 5, 2004
10.3.8 will run fine, my 333mhz imac has it right now... The firmware issue is when going from 9 to 10.anything as supposently if you dont upgrade the firmware your mainboard would fry when going from 9 to 10.

You dont need to do anything once your on 10.anything to upgrade to a higher version.
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