using 10.5.7 beta ati drivers (jsut five kexts) and new natit, i got my 4850 working in 10.5.6 Leopard
You need to have OSX 10.5.6 or higher
What’s working – qe/ci, resolution change
currently only second dvi port works for me, and only with dvi-vga adapter
also, Display is recognized as standart vga/svga display, so only 4:3 resolutions available
only usefull for VGA connections – with switchresx(before using it, make sure u can change resolution) help i added 1680×1050 mode jsut fine
EDIT3(for4850): booted with dvi2vga(converter only, no monitor attached to it) in second port, and dvi connected to first port(closest to mobo), and voila,
display on first port properly recognized.
some vertical little screen jerkness sometimes
Pkg with drivers you will find in #radeonhd room on irc.osx86.hu
and now some screenshots
User with 4870 reported he has almost no problems with 4870, he just cant change resolution, results in black screen
Btw, 10.5.7 kernel also supports Nehalem i7 fully now.
P.S. I hope no other company than Apple/AMD will pretend they wrote drivers for 4850/4870 or nehalem i7