LG UltraFine 5K Build

[wladdych]

Are you sure that you get the full 5K resolution? How you managed two DisplayPort connections on this board? UltraFine 5K requires two, because it uses dp 1.2, not 1.4

With single DP connection I see boot screen on cold boot too, but then I get up scaled (from 4K) 5K resolution instead of real. To get real 5K I need to connect the second DP after boot.

Yes. 5k over single DP cable.

 

[etc]

Yes. 5k over single DP cable.

It always shows 5K in Sys Info. You need to check real resolution via SwitchResX

 

[wladdych]

It always shows 5K in Sys Info. You need to check real resolution via SwitchResX

switchresx shows 2560 x 1440 for both displays but second display is 100% in 5k mode.

 

[etc]

switchresx shows 2560 x 1440 for both displays but second display is 100% in 5k mode.

See the right res here:

If it shows scale resolution base as 3840x2160, that means you don't get 5K actually.

 

[etc]

I'm sceptical about single DP connection because UltraFine does not support DP 1.4 and uses DP 1.2 which actually can't run 5K using single connection, so it uses two DP 1.2 for each half of the screen. Maybe your mb's TB controller splits DP 1.4 (or use 2 streams, whatever) signal into two DP 1.2 for UltraFine, but I am not sure that this really works.

 

[wladdych]

See the right res here:

View attachment 531646

If it shows scale resolution base as 3840x2160, that means you don't get 5K actually.

you are right, it shows scale resolution base as 3840x2160 for ultrafine, and 5120x2880 for second monitor.

 

[etc]

you are right, it shows scale resolution base as 3840x2160 for ultrafine, and 5120x2880 for second monitor.

Sorry, but I don't know what's your setup here. What is "second monitor" and how it's connected? What's the first monitor? How it's connected too?

 

[wladdych]

Sorry, but I don't know what's your setup here. What is "second monitor" and how it's connected? What's the first monitor? How it's connected too?

second monitor is planar ix2790 connected to dp 1.4 to gpu directly
first monitor is lg 5k connected with thunderbolt cable to gigabyte's z590 vision d onboard thunderbolt controller.

 

[etc]

second monitor is planar ix2790 connected to dp 1.4 to gpu directly
first monitor is lg 5k connected with thunderbolt cable to gigabyte's z590 vision d onboard thunderbolt controller.

Ok, I understood now. So it seems there's no way to get 5K using single connection and that's why you see boot screen. Happily you have a Planar 5K monitor and can use it fully. In my case there're no other options for 5K displays except UltraFine and ofc expensive XDR.

 

[joevt]

Use SwitchResX to create a Custom Resolution of 5120x2880@39Hz mode (using CVT-RB2 timing) for the LG UltraFine 5K. If it doesn't work, start from 30Hz and see how high you can go. If still nothing, then try CVT-RB timing.

To see the current timing, go the Current Resolutions tab in SwitchResX, find the currently selected Resolution, and double click it. It should show pixel clock, active pixels, refresh rate and scaled pixels.