i got the new RX590 and was hoping to drive my BenQ EW3270U at 4k, 60hz, 10bit.
It's connected via a DP 1.4 cable, which should have enough bandwidth for that... afaik.
In my Radeon driver settings, i can select 10bpc or 12bpc, but for whatever reason, it jumps back to 8bpc after the screen turns black for a second or so.
(It stays at 10bpc if i lower the resolution to Full HD though, I'm not really sure whats going on here).
(Windows' "HDR" mode is turned off... if i turn it on, the driver sticks to 10bpc, but i can't raise the refresh rate above 30hz)