Hi. I'm trying to install High Sierra in a 775 build with q9550 and Sapphire Dual-X R9 270X OC 4 GB with this GPU-Z specs:
https://www.techpowerup.com/gpu-specs/sapphire-dual-x-r9-270x-oc-4-gb.b2722. which is supposed to work OOB but I can only reach black screens and no signals.
I tried all kinds of combinations with clover, lilu and wg, injecting framebuffer, patching kexts, etc... but I could only initialize the system in safe mode, graphics recognized as Amd Radeon HD 7xxx 4096 Mb and id device 0x6810; or using, this is a bit weird, id device 0x6811 with inject ati and fix display, in which case recognized as Amd Radeon R9 270x 8 Mb Vram and id device 0x6811 and of course without acceleration in any case.
I have run out of ideas and would like to ask for your help, thank you for your great work and apologize for my bad English
Send me iMac-de-woland.zip