https://imgur.com/gallery/NY0C3Rk
This started because I wanted my childhood computer back. 68 k MacIntosh. I decided to get one a little bit better that was a power PC but in the same form factor. Then I realized there was just one step above that to allow for a G3 upgrade which of course I bought.
Of course now I went from reliving nostalgia to maybe playing more modern things. Spoiler alert, because of frontside bus limitations, IRQ things, A G3 upgrade does not A G3 make.
I got an idea though; could I fit another motherboard in the old form factor case? …. Yes, yes I could.
Overclocking the G4 front side bus from 133 to 160 MHz netted nearly a 12% boost in memory performance alone. The AGP slot has separate crystals, so that remains stable. I experimented clocking that up but timing issues prevented it. The CPU started at 733 megahertz and in the end I had a dual CPU 1.72 GHz system.
Rather than paying exorbitant money for upgrade cards from the various manufacturers, I purchased a standalone daughter card with dual CPUs on it and modified that, it's firmware, it's cache, picked up a couple newer CPU dies off eBay, and went well beyond the 1.2 GHz clock limit of days gone by.
Cooling with a challenge, custom ductwork, lots of modifications to make a full size tower computer fit into a relative pizza box.
I plan to stream games off this at some point, but I am now able to run Warcraft 3, Halo, Doom3, I can browse YouTube on this, it has access to my 200 terabyte NAS, it can even screen capture in real time and write to my NAS.
This total build took about a year. A lot of figuring things out, seeing what's possible, there's still a couple small things I'd like to do to it but by and large it's functional