Custom Resolution Utility (CRU)

[bitsonic]

(12-11-2023 10:06 PM)ToastyX Wrote:  

(12-11-2023 12:41 PM)bitsonic Wrote:  Hi, I am using a Dell Latitude 5440 (support DP1.4 DP alt mode) to connect to my ASUS XG43UQ monitor (supports up to 4k 144hz) via a DockCase 8-in-1 smart dock. The dock equips with a PS186 DP to HDMI micro-chip, which supports DP1.4 input and HDMI2.0b output. I enabled the 4-lane DP alt mode in the dock configuration menu.

I set 4k refresh rate in Display ID 1.3 slots. The highest refresh rate I can get is 67.5hz. Any rate higher than that would not appear in the Win11 display drop down list. Looks to me it is somewhat related to 600MHZ pixel clock limits of the dock.
So, my question is - Is there a way that I can override this limit and force a higher refresh rate for my 5440?

That sounds like a graphics driver-imposed limitation because DisplayPort 1.4 HBR3 should support up to 1080 MHz pixel clock at 8 bpc. If there are HDMI data blocks, delete them since they aren't needed for DisplayPort. If the range limits is included, set it to 1080 MHz. The driver might be listening to one of those.

Tried both suggestions, no avail. Still don't get the refresh rate in the drop-down list. Anything else that graphics driver may be listening to?

BTW, I suspect that the dock may pass 600MHZ pixel clock limit to the laptop, because it only has a HDMI2.0 downlink port although it has a DP1.4 uplink port.