help setting up LG CX OLED with Radeon 6800 XT

[bwana]

S0 I got an '8k certified 6 foot hdmi cable' , not because I have an 8k tv but because I dont want to deal with possible cable issues. From monoprice it was not too bad. Then I plugged it in to the HDMI port of the 6800xt, (Windows 10 build 1909) and also port#4 on the TV (the one on the back that says 120hz).

Then I hit input select button on the remote (looks like an RCA plug in between the Netflix and Prime video buttons) , scrolled to the left and hit dashboard. Then I went to the top right where there is a little gear with a green underscore - 'settings'? I hit that and scrolled down to HDMI 4 and changed that to PC. I am told this is needed to get the LG as a PC display.

Then I hit the gear icon on the remote and brought up the settings menu along the left margin. Scrolled down to ALL settings. Then went to picture then picture mode settings. Here I selected 'game mode'. Contrast, brightness I left alone. I went down to options. Turned off motion eye care and the went down one to Tru Motion and set that that to OLED Pro Auto.

Then I went back to ALL settings-> picture->Additional Settings and set Ultra Deep Color, Instant Game response, and AMD Freesync Premium to on.

Now I went to the Radeon control Panel, hit the gear icon in the top right and selected the Display tab. Here I turned on Adaptive sync compatible. Color depth is 10 bpc and Pixel Format is YCvCr 4:4:4.
Display specs says this:
Timing Info Horizontal Vertical
Timing Total 4400 2250
Timing Display 3840 2160
Timing Front Porch 176 8
Timing Sync Width 88 10
Timing Polarity positive positive
Interlaced/Progressive progressive
G.Pixel Clock 594000
G.RefreshRate 60
HDMI link status monitoring disabled
Current Link Settings not available
AMD Freesync Refresh Rate 40 to 60 Hz reported by display

Well, that's not right (60Hz?) so I tried to make a custom resolution
I created a custom resolution with these settings:
Resolution 3840x2160
RefreshRate 120
Presentation progressive
Timing standard manual
G.Pixel Clock 497750
G.RefreshRate 39.859
Timing Info Horizontal Vertical
Timing Total 5392 2316
Timing Display 3840 2160
Timing Front Porch 352 3
Timing Sync Width 424 5
Timing Polarity positive positive

Hit save and it said 'This base mode combination already exists. Do you want to replace the existing settings. Well, since I couldn't find any of the 'base modes' I clicked save.

Went to blurbusters motion tests and the flying saucer guy was laughing at me saying 60Hz.
Went back to create another custom resolution but it seems it only shows one. No matter how many times you click 'create new' , if you use a specific resolution, it only lists that one.

I tried

So I went back to create a new resolution changed
Timing Info Horizontal Vertical
Timing Total 4400 2250
Timing Display 3840 2160
Timing Front Porch 176 8
Timing Sync Width 88 10
Timing Polarity positive positive
G.RefreshRate 120

Hit save , said yes to the confirmation box, the display blinked at me but UFO guy still said 60Hz.

I havent had this much fun since configuring a display Geforce 2 MX card in a pentium 3 running windows xp.
So then I right clicked on the desktop, clicked display settings and changed resolution to 2560x1440. Why do I not get to choose a refresh rate in this silly new settings panel? Anyway I did that then went into the Radeon panel->settings->Display and created a new custom resolution

Resolution 2560x1440
RefreshRate 120
Presentation progressive
Timing standard CVT-Reduced Blanking
G.Pixel Clock 497750
G.RefreshRate 119.998
Timing Info Horizontal Vertical
Timing Total 2720 1525
Timing Display 2560 1440
Timing Front Porch 48 3
Timing Sync Width 32 5
Timing Polarity positive positive

The UFO guy is still saying 60Hz.

So now I am here asking for help.

[ToastyX]

The CX should already have 120 Hz defined by default. You shouldn't need to add any custom resolutions. You have to change the both the resolution and the refresh rate through the Windows display settings. AMD's control panel doesn't have a way to set the current resolution or refresh rate because they didn't want to duplicate the Windows display settings.

The first timing is correct for 3840x2160 @ 60 Hz.
The second timing is messed up. You created 3840x2160 @ 39.859 Hz using CVT timing (meant for CRT monitors) and saved it as 3840x2160 @ 120 Hz.
The third timing is correct for 3840x2160 @ 120 Hz, but it should already exist by default.
The last timing is correct for 2560x1440 @ 120 Hz, but it should already exist by default.

You didn't ever mention setting the refresh rate in the Windows display settings (under advanced settings), so it was probably at 60 Hz the whole time.

[bwana]

(01-15-2021 09:22 PM)ToastyX Wrote:  You didn't ever mention setting the refresh rate in the Windows display settings (under advanced settings), so it was probably at 60 Hz the whole time.

https://ibb.co/FYBCMFQ

Win10pro 1909

Where is the refresh rate?

---

wow I finally found it ....kind of obscure
https://ibb.co/rxkZC09

[ToastyX]

The latest version of Windows 10 (20H2) has it under the display information without needing to go into the display adapter properties. The refresh rate for the current resolution is actually in the monitor tab, but "List All Modes" also works.