When I installed Ubuntu Mate 16.04 on my 12’ mid-2005 iBook G4 it worked great after I added in radeon.agpmode=-1 to the boot parameters. However, I’m still unable to use 3d and I only get 2d acceleration. Are there any patched debs like with Debian or is there another fix?
It doesn’t mention anything about the R300 problem.
It’s mentioned here, but the patched files are only for an older distro, is there a similar fix for 16.04?
https://wiki.ubuntu.com/PowerPCKnownIssues
just a stoopid question: what do you Need 3D for on a RV300?
For 3d games like Q3A and other programs that take advantage of video acceleration.
hmmm, just Play Q3A on ibook OSX-Partition?! 
sorry, don´t know how to solve this - seems, old Apple PPC´s are not really supported out of the box, you have to fiddle with kernel patching and compiling Software and so on, to make things work.
Sad, but true…