Hey yeah I completely understand you
@MrCheeto. I am looking for this exact same problem - what GPUs are supported on OSX Leopard 10.5. Snow Leopard is butting into every search result.
I'd really appreciate 2 things:
1. Comprehensive list of GPU chips (not finished GPU models tyvm) that work with 10.5
2. Where to get the drivers
I've stumbled upon some tonymacx86 article from 2010 that listed GPUs but for Snow Leopard and it wouldn't give you a generic idea what chips are supported, instead what actualy GPUs you can go and buy in Tony Mac's favorite shops I guess? I'm keeping an eye out for a G5 on local listings, but it's an AGP model so I'm screwed. Either that, or I wait for a PCIE G5 to arrive.
And the drivers. Boy is this frustrating. I tried nVidia's own search thing and the support is spotty at best. While 10.5 does show up as an OS for a couple cards (100 series, 300 series, and other oddballs with no rhyme or reason) it doesn't yield any results for one thing, and it doesn't even show up for the cards that actually shipped with the damn computer.
As for AMD, I've already been frustrated enough looking for their drivers for Linux back in 2017. They improved i.e. they made crap drivers in 2017-2019 only to finally have fully working (i.e. no embarassing ****ups like no display over anything newer than DVI) drivers integrated into the kernel source tree - therefore voiding the need for AMD to offer separate drivers. This just doesn't inspire me too much to spare the time to search for their drivers. I'll get to that maybe when I'm less loaded with work.