I have a Samsung ju6400 and an AMD R9 390. The adapter was working fine and I could do 4k at 60hz. All of a sudden this past week, it can only do 4k at 30hz. The option is completely gone now on the TV. I have all the correct settings that were working previously but this past week I have not gotten 60hz at all when I change it on the display properties. I rolled back to a previous driver as well on the AMD card but that was not the issue. I ended up buying a 2nd cable adapter, but its the same issue with the new one I bought. I have done the whole PC mode and Game mode on the TV settings, and it still does not show 60hz is available. Anyone have any thoughts?
Soulgank
Hi Soulgank,
What driver version you have running now ?
I know that most setups with TV work best when making a custom resolution for 3840×2160 at 60Hz with Timing Standard set to CVT-Reduced Blanking.
With all AMD Drivers after 16.8.3 this will be a problem because i think AMD just took that option out for all drivers after that !?!?
I case you are running a newer driver thatn 16.8.3, please ininstall that end instead use 16.8.3, you can find that here:
http://support.amd.com/en-us/download/desktop/previous/detail?os=Windows%2010%20-%2064&rev=16.8.3
From 16.9.1 onwards AMD made many chages for RX400 series but very liitle to none for previous generations GPU’s so even with that “older” driver you are not missing much …

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