Enabling HIP alone in Blender is very easy, and it can be done by passing a couple of extra options to CMAKE, and obviously you have to compile from source. I’ve added this when editing AUR PKGBUILD for blender-git version:
-DWITH_CYCLES_DEVICE_HIP=ON \
-DWITH_CYCLES_HIP_BINARIES=ON \
-DCYCLES_HIP_BINARIES_ARCH=gfx900 \
where gfx900 is my Vega 64 arch from rocminfo output, I think RDNA 1/2 is included by default
If you have a non-RDNA GPU you also have to tweak some major/minor arch vars in util.h iirc, and I don’t actually know what they’re responsible for and noone will probably tell us, the old commit rB2f89ddc04377: Cycles: eliminate HIP architectures that fail to build that added HIP bins to be built for more GPU arches is now deleted, so just forget about it.
And building ROCm from source is an adventure of it’s own for several days with numerous build errors that have to be addressed every time. I just don’t bother anymore.
I feel so dumb now for picking Vega over RTX looking forward to years of support that AMD was known for at the time, for better support by open-source drivers. Nvidia proprietary Linux driver is horrible, there’s no overclocking or fan/power management support etc. But this thread just screams at me “Go buy Nvidia as soon as prices settle down and forget AMD GPUs as a bad dream!” Such a spit in the face of AMD users by essentially taking away GPU rendering, the lack of communication, this thread is a joke. At least AMD developed a great CPU to render with that doesn’t require “”“the driver”"" to work, but still times slower than GPU rendering.