I am clueless what is wrong with my setup that won't use my new 4K screens with their native resolution. Before I would return the screens day after tomorrow, I thought I give it a last try and ask here. I've got a notebook (Thinkpad T15 Gen. 1) on a dock and so far I used 2x 24" WUXGA 1920x1080 without problems. Of my two new 4K screens, the first uses it's 3840x2160 but the second only 1024x786 (with DP cable) or 800x600 (with HDMI cable).
So the problem does not depend on
- the sort of cable (DP/HDMI)
- whether the notebook screen is in use or not (usually it's not).
- It seems not to be the quality of the cables. At first, the screens complained I should use the cables supplied with them (which I did). Then I bought new HDMI cables which are supposed to comply to the highest standards and the screens didn't complain any more. But the problem persists.
Hardware setup:
- Notebook: Thinkpad Lenovo T15 Gen. 1 (Model 20S6003NGE with 15,6" UHD = 3840x2160 Display)
- Graphics adaptors*: Intel UHD Graphics + NVidia GeForce MX330
- Dock: ThinkPad USB-C Dock Gen 2 (model 40AN)
- Connectors: 2x HDMI, 2x DisplayPort
- Screens: 2x LG 27UL550-W (3840x2160 @ 60 Hz)
*Specifications of the notebook: Intel UHD Graphics in processor and NVIDIA GeForce MX330, 2GB GDDR5 memory; supports up to 3 independent displays via native display and two external monitors; supports external monitors via HDMI (up to 4096x2160@24Hz), USB-C (up to 4096x2304@60Hz) or Thunderbolt (up to 4096x2304@60Hz)
OS: Windows 11 Pro (10.0.22621.3155)
In "Display and Video Output Configurations - Docking Stations" (https://support.lenovo.com/de/de/solutions/pd029622) Lenovo states that the specific combination of computer and dock works for 2x external 4K + 1x internal 4K.
What I have tried so far: (Sorry, I have to translate back from German, I hope you can follow.) System settings > Display
- Screens are recognized correctly, but one is set at low res.
- Selected the screen with correct resolution and set "extend this screen"
System settings > Display > Advanced Display
Display 1: LG HDR 4K Display information: LG HDR 4K Display 1: Connected to Intel(R) UHD Graphics Desktop mode 3840 x 2160, 30 Hz Active signal mode 3840 x 2160, 30 Hz Bit depth 8-Bit with Dithering Color format RGB Color space HDR (High Dynamic Range) [or SDR (Standard Dynamic Range), doesn't make a difference for the other display what I select here.] HDR-certification not found Brightness max 295 Nits Display adapter properties for Display 1 refresh rate: 30 Hz (selectable: 29,97 Hz or 30 Hz)
Display 2: LG HDR 4K Display information: LG HDR 4K Display 2: Connected to Intel(R) UHD Graphics Desktop mode 1280 x 768, 60 Hz Active signal mode 1280 x 768, 60 Hz Bit depth 8-Bit with Dithering Color format RGB Color space SDR HDR-certification not found Display adapter properties for Display 2 refresh rate: 60 Hz (selectable: 59,94 Hz or 60 Hz)
This is all only display, stating the current status, nothing interactive to do any settings, except the last two items, adapter properties and refresh rate. Is this supposed to be like this? When I had first connected the new display, for no. 2 "desktop mode" was still shown as 3840 x 2160 and as signal mode 800 x 600.
Display adapter properties > List all modes I get to choose from all resolutions from 640x480 up to 1280 x 768. After I first selected a different resolution here, both "Desktop mode" and "Active signal mode" were shown in the list as the same low resolution.
In the device manager everything looks all right, concerning screens, display adaptors and everything else.
Looked for driver updates. None, for both adaptors. (Intel would have one but recommends not to use it because it would not contain device specific alterations my hardware manufacturer may have made.) Installed LG's driver "Win10 Driver LG_HDR_4K.zip 07/06/2023". Only effect: Now I can set HDR for the first screen.
Installed firmware update for the dock and for Intel Management Engine Firmware.
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Might it work with the GeForce? Windows seems to use only the Intel one. Can I make Windows use the GeForce? In the Nvidia settings I can set settings concerning 3D, but not generally. Under System > Settings > Graphics I can select adaptors for specific applications, but not generally
Does anybody have a hint what to try or how to search further?
Best regards, Joachim
