I'm using 3 monitors currently on an RX590 using latest drivers on win10 fully updated.
1. 1440p 144Hz 10bit HDR (displayport)
2. 4K 60Hz 10bit non-HDR (displayport)
3. 4K 60Hz 8bit HDR (HDMI 2.0)
All running at RGB444 with 10-bit pixel format disabled, but have tried every possible combination without luck.
The issue I'm coming up against is an inability to turn on HDR depending on which monitors are active.
If I have only monitor 1 or 3 active, I can turn on HDR at their max resolution/refresh no problem.
If I have more than 1 monitor active, monitor 1 won't turn HDR on above 100Hz and monitor 3 caps at 30Hz.
It's obviously not a problem with the monitors or the cables as they all function properly when used by themselves. Gotta be the GPU.
Is this normal?
