Question Display Port widescreen output broken after reformat/reinstall Windows

[goblynn93]

I have several 17" Sager laptops with 3080ti, 4070 or 4090 RTX GPUs. They all have Intel chips and Optimus for the RTX.
We have used the laptops with success to feed super wide images to custom screen setups.
Resolutions would include things like 4320x1080.
We use Display Port connections to a BARCO E2 to handle switching.
The BARCO E2 can't handle resolutions above 3840 on HDMI so we must use Display Port.
Everything worked fine - and then I reinstalled Windows on all the laptops.
Now widescreen over Display Port will not work.
The BARCO E2 thinks it is seeing a widescreen signal but the images we get are truncated and not filling the pixel space.
I have tried everything... reinstall Windows. Complete removal of all GPU drivers for both Intel and nVidia and reinstall. New adapter, new cable, different E2, different EDIDs, nothing seems to work to bring back wide screen capabilities over Display Port.
HDMI works fine for widescreen. For example, 3840x1080 works on HDMI but it does not work on Display Port.
Sager tech support has been very responsive but they have no idea what might be wrong. I am no stranger to reinstalling Windows. I've been maintaining laptops for production companies for decades and I've never seen an issue like this. These days reinstalling Windows is one of the easier things I do!

This is happening with all my 17" Sager laptops (8 machines). My 15" Sager laptops do not have this issue. They are all 1060 or 1070 GTX, older cards.

You can see in the image that the two widescreen outputs -should- be mirrored. The screen next to the laptop is showing the E2 "muti-view" preview of the signals it is receiving. The HDMI (bottom) is fine, but the Display Port (top) is broken.

https://imgur.com/a/74EdoEn

 

[helpstar]

did you install the mobile gpu drivers from the laptop´s manufacturers support homepage and not from nvidia.com or intel.com?

which settings on the dp input can you alter in the intel driver?
what resolutions can you chose? is landscape selected?

 

[goblynn93]

did you install the mobile gpu drivers from the laptop´s manufacturers support homepage and not from nvidia.com or intel.com?

I have tried both the drivers from Sager's driver page and the Intel and nVidia drivers from their download pages. Same results as far as the Display Port output.
I even went as far as following the Sager "reinstall Windows" step by step based on their user manual - something I've never done - at Sager's suggestion. They said some devices would need to load in a certain order to find everything properly. The step-by-step re-install did not help the Display Port issue.
Sager tech support also told me that they use the drivers from Intel and nVdia and instructed me to download direct from Intel and nVidia for the latest versions.

which settings on the dp input can you alter in the intel driver?

In the Intel Graphics Command Center I do not have options to make changes to the DP settings. Graphics Command Center opens the Windows Display settings controls for that.

is landscape selected?

Display Orientation is set to Landscape.

what resolutions can you chose?

Resolution choices in the Windows Control Panel are all your standard 16:9/16:10 resolutions (e.g. 1920x1080, 1920x1200, 1280x720, etc) with the one exception being "3840x1080 (Recommended)" which is my current EDID coming from the E2.

Under Advanced Display>Display Adapter Properties>Adapter Tab>List All Modes I can see 3840x1080 at most standard frame rates (59, 60, 24, 29, etc). Changing the refresh rate results in a different truncation of the image. I see more or less of the image but never the whole thing.

I am currently using a DP 1.2 to USB C adapter (with a DP 1.2 cable and a DP 1.2 input on the E2, all tested and working at widescreen resolutions with my personal laptop). The laptop also has a dedicated mDP connection. I get the same truncated results with both the adapter and the mDP direct port.

nVidia Control Panel shows the Display Port (and HDMI) connections coming direct from the RTX 3080 ti while the local laptop monitor is connected to the Intel Iris.

I was incorrect about GPU models. I have two 3080 ti, four 4070 and two 4090 mobile cards (we buy laptops in pairs). They are all showing the same issue with widescreen output using Display Port connections.

Mirrored or Extended mode HDMI works, Display Port does not.

edit: many edits to correct mistakes