Hey i got the exact same issue with a Samsung HU7505 4k60 television using amdgpu on xubuntu 16.04.1/16.10, amdgpu-pro-16.50-362463 drivers work in 4k60 until the display is turned off and then it gives "mode not supported" both the bios and the edid from the display while on crimson 16.12 https://f001.backblazeb2.com/file/nwgat-cdn/misc/xfx-rx460-Baffin-bios.rom https://f001.backblazeb2.com/file/nwgat-cdn/misc/samsung_uhd_colour_YCbCr444-4k60_edid.bin amd-staging-4.7 kernel, made no difference (git pull today) ubuntu 4.10 from kernel.ubuntu.com/~kernel-ppa/mainline/v4.10-rc2/ might also be related to black screen on 4k60 issue i have on windows https://www.reddit.com/r/Amd/comments/5fyy7c/december_tech_support_megathread/dbwa536/?context=3 System Configuration: Motherboard: FM2A88X-ITX+ AMD A88X CPU: AMD A10-7800 Memory: 16GB DDR3 GPU: XFX RX 460 2GB (RX-460P2SFG5) GPU-Z Report: https://www.techpowerup.com/gpuz/details/4qq9n VBIOS: 015.050.000.000.000000 Driver: amdgpu OS: xubuntu 16.04.1 LTS AMD64 or 16.10 AMD64 Display: Samsung UE55HU7505 55" UltraHD (in UHD Colour Mode) Display Cable: Startech Pro Series Metal High Speed HDMI Cable 2M (HDPSMM2M) from samsung manual http://downloadcenter.samsung.com/content/UM/201411/20141127124859330/[ENG]NUDVBEUH-1.111-1015.pdf CEA-861 3840x2160 50Hz 112.500 50.000 594.000 +/+ 3840x2160 60Hz 135.000 60.000 594.000 +/+ 4096x2160 50Hz 112.500 50.000 594.000 +/+ 4096x2160 60Hz 135.000 60.000 594.000 +/+