WD19DSC + Precision 3581 => no 2 x 4K

Hello!

Some more info:

- I archived 2 x 4K also on with my Precision 3581 but the solution is still not perfectly satisfying.

- What I needed to do is to plug one monitor on the HDMI plug of the 3581 and the second monitor on the DP of the WD19DCS.  With this configuration i can display 3840 x 2160 on both external screens (and 1920 x 1080 on the laptop monitor itself).

- So for me it seems that the bottleneck is the USB-C port of the 3581, since other reasons are ruled out:

*) obviously the graphic card of the 3581 is sufficient to generate data for 2 x 4K (60Hz).

*) The WD19DCS seems not to be the bottleneck, since it works fine with my HP laptop to supply 2 x 4K via the DP on the WD19DCS.

-) Since I frequently change between Dell and HP laptop, it would be great if I only need to plug the USB-C cable to the WD19DCS and not additionally have to fidle with the HDMI cable.

Any idea on how to improve?

Thanks,

   Bernd

Hi!

After digging deeper in the manuals, I found out that:

- The laptop needs to support HBR3, so that the WD19DCS can provide 2 x 3840 x 2160 @ 60 Hz. 
see table 2, at https://dl.dell.com/content/manual35047404-dual-kabel-f%C3%BCr-dell-dockingstation-wd19dcs-benutzerhandbuch.pdf?language=de-de#unique_5

- There is a list of Dell systems, which provide HBR3. However the 3581 is neighter in the list of supporting devices nor in the the list of not supporting devices:
https://www.dell.com/support/kbdoc/de-at/000183937/dell-systeme-die-hbr3-spezifikationen-unterstuetzen

- To check compability there is the suggestion to check via intel Search. 
The i7-13700H supports a max Resolution (DP) of 7680 x 4320 @ 60 Hz so should be capable of HBR3:
https://www.intel.com/content/www/us/en/products/sku/232128/intel-core-i713700h-processor-24m-cache-up-to-5-00-ghz/specifications.html?wapkw=%20i7-13700H

- On other side i got the hint that for HBR3 you need to disable some hint (link lost), that you Need to DISABLE "Switchable Graphics" in the BIOS. 
For other Precision laptotps it is stated the BIOS Option "Discrete Graphics Controller Direct Output Mode" needs to be activated. 

Unfortunatly I couldn't find these options in the BIOS of the 3581. I tried to DEACTIVATE "Adaptive C-States for discrete graphics" but this didn't give an improvement.

- So my suspicion is that 1 cannot run HBR3 (and therefor not 2 x 4K)  through the WD19DCS, since a BIOS Option for "Discrete Graphics Controller Direct Output Mode" is not implemented in the 3581.

My Question:
- Is this a correct Interpretation?
- Can I expect that the required BIOS Option will be implemented in an later update? (When is it on your roadmap?)

Thank you, 
   Bernd