PC Drivers & Software

[avalon_]

Hi All,

I seem to have a problem with my new 6900XT, it won't allow me to change the refresh rate on my monitor (Samsung G8 Neo, DP 1.4 via Ultra Speed 80gbps DP cable) in Windows 10. I have tried the latest AMD drivers. The settings won't go anywhere above 120hz, even after I change the refresh rate to 240hz in monitor settings.

Thank you in advance!

[DimkaTsv]

"DP 1.4"
Here is your answer!.

DisplayPort 1.4a supports only up to 4k 120Hz refresh rate. 
To use 4k 240Hz you need either DP 2.0+ with UHBR 20 transfer mode (77.37 Gbit/s), which is not supported by either your monitor, GPU's of RX 6000 series or RTX 3000 series as well iirc, because it is recent standart (and i am impressed by it's speed comparatively)
OR!, You can use HDMI 2.1 with DSC (display stream compression) 

Those adopter issues... What even you will be able to play at 4k 240 fps? 

[avalon_]

No, you are incorrect. I finally managed to get it working 4k 240hz after installing all the updates. And I can play a variety of games in 4k with more than 240fps, for example CS GO, F1, Doom, Strange Brigade to name just a few

[DimkaTsv]

I mean, congrats, but that also means that info on input was incorrect. 
Maybe it does have DP 2.0 at least? Because DP 1.4 SURELY cannot do 4k240. Even with YCbCr 4:2:2, probably even with YCbCr 4:2:0. 

Also FPS doesn't equal monitor refresh rate. I can do 1000+ FPS, but my monitor still only works on 144 Hz

[SilasD]

DP1.4 can certainly support 4k240Hz, it just needs to do so via compression. With DSC, DP1.4 can support around 26Gbps and 4k240Hz will run at around 23Gbps. So, there's not much headroom, but it still shouldn't be a problem. Where it would fail is with DSC disabled.