4K Active signal resolution on 1440p monitor?

[dinkostinko]

Hello everyone,

 

I have two identical LG Ultragear 27GL83A-B monitors connected to my Lenovo Thinkpad E15 Gen 2 with an AMD 4700U CPU with Radeon Graphics.

 

-One monitor (Display 1) is connected via Displayport to a Thinkpad Universal USB-C Dock, and is running at 2560x1440 @120hz.

-The other monitor (Display 2) is connected directly to my laptop via HDMI and is showing as 3840x2160 and cannot be set above 60hz.

 

Why is the "Active signal resolution" for Display 2 shown as 3840x2160 when it's definitely a 1440p monitor?  I have tried setting a custom resolution in the AMD adrenalin software but have not had any luck so far.  Would love some direction on this issue because the pixel scaling is weird and it makes text hard to read.  Thank you!

[Alex Atkin UK]

46 minutes ago, dinkostinko said:

Hello everyone,

 

I have two identical LG Ultragear 27GL83A-B monitors connected to my Lenovo Thinkpad E15 Gen 2 with an AMD 4700U CPU with Radeon Graphics.

 

-One monitor (Display 1) is connected via Displayport to a Thinkpad Universal USB-C Dock, and is running at 2560x1440 @120hz.

-The other monitor (Display 2) is connected directly to my laptop via HDMI and is showing as 3840x2160 and cannot be set above 60hz.

 

Why is the "Active signal resolution" for Display 2 shown as 3840x2160 when it's definitely a 1440p monitor?  I have tried setting a custom resolution in the AMD adrenalin software but have not had any luck so far.  Would love some direction on this issue because the pixel scaling is weird and it makes text hard to read.  Thank you!

Everything I can find suggests the 4700U can only support 4K 30Hz or 1440p at 75Hz as it only supports HDMI 1.4.  So I think its glitching here in some way.

[Glenwing]

Some 1440p monitors accept 4K resolution input signals on HDMI. This is for compatibility with older consoles (PS4, Xbox One) which only let you choose between 1080p and 4K. So on 1440p monitors they would be forced to a 1080p limit. To avoid this, monitors accept a 4K signal and then downscale internally to 1440p.

 

If you have GPU Scaling enabled in the AMD Adrenaline settings, the graphics card will always output a signal at the monitor's maximum resolution regardless of what resolution you set the desktop to. If you choose a lower resolution, it will upscale it to the monitor's maximum resolution before transmitting. Unfortunately this combines in a bad way with the 1440p monitors that accept a 4K signal, as it just takes your 1440p original image and upscales it to 4K, transmits it, and then it's downscaled back to 1440p on the other side, resulting in quality loss from the double conversions, and also limiting you to 60 Hz because of the increased resolution during transmission.

 

To avoid this, turn off GPU Scaling in the graphics card control panel, or don't use HDMI.

[dinkostinko]

15 hours ago, Glenwing said:

turn off GPU Scaling in the graphics card control panel, or don't use HDMI

GPU Scaling has been turned off the entire time, yet text is still visibly blurrier on Display 2 than it is on Display 1.

 

I unfortunately have to use HDMI as the USB-C port does not have the bandwidth to support two 1440p monitors.

 

Turning on GPU Scaling defaults the resolution to 4K, and limits me to 30hz.  How do I make it so I am outputting a 1440p signal over HDMI just like I am over Displayport?

[Glenwing]

On 3/29/2024 at 12:23 PM, dinkostinko said:

GPU Scaling has been turned off the entire time, yet text is still visibly blurrier on Display 2 than it is on Display 1.

 

I unfortunately have to use HDMI as the USB-C port does not have the bandwidth to support two 1440p monitors.

 

Turning on GPU Scaling defaults the resolution to 4K, and limits me to 30hz.  How do I make it so I am outputting a 1440p signal over HDMI just like I am over Displayport?

Sounds like AMD is not implementing something correctly in their driver.

 

Download the Custom Resolution Utility here: https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU

 

Select the 1440p monitor at the top, then select the CTA-861 extension block and click "Edit":

 

Select the TV Resolutions data block:

 

Delete all the 4K entries:

 

Click OK on everything, then restart the graphics driver using Restart64.exe

 

Then the 4K profile should be gone, and it should use 1440p.