You are hitting the display port bandwidth limit. Dropping the frames to 98hz will give you full color range, any thing faster will sacrifice color depth to push more frames. I'm running my PG27UQ at 98hz because of that.
Vangry wrote:Hows this monitor version compared to the XG438Q?
Not true. With DSC I should be getting 144hz@4K with RGB FULL 10 bit go figure.
As far as I understand it, only certain 2000-series cards and the new 3000-series cards include the DSC specification to their DisplayPort implementations. Your 1080 card doesn't support DSC, regardless of which drivers you install.