https://forums.freebsd.org/threads/drm-kmod-amd-richland-radeon-hd-8670d.69464/#post-416483
Please read this thread carefully
This can be amdgpu or atiradeon depending on the generation of your hardware
When AMD took over ATI they rebranded first the driver in amdgpu still to run Radeon chips.... so this is the source of confusion
So that's answering to the second message. Later, AMD dropped the brand "Radeon", things became clear
So yes, late Radeon chips may run with amdgpu.ko instead of radeonkms.ko
You must try either and choose the more stable
Stop hearing people that want you set up full DRM-KMOD, as many people want that everybody setup ZFS over UFS with no regard to the hardware.
RUN TESTS BY YOURSELF
If full DRM-KMOD is found unstable on your system, if 3D apps don't run correctly, don't insist switch to legacy drm kmod
DRM-KMOD is just a alternate driver coming from Linux, FreeBSD Legacy-kmod + Xorg drivers still exist, we are still free to choose the best solution in a given situation. As today, it is false to consider DRM-KMOD as superior. This is only an alternate solution that works well for recent hardwares, but that can raise issues with older hardwares.
DRM-KMOD being a port from Linux, not something developped natively for BSD.... there are always some limitations when running on BSD, so we must take care before referring to the "Linux experience"