So as not to hijack @rhyamamoto's other thread.....

I've been doing a lot of research on this lately. From what I've been able to discover on the Dell forums, the Precision 7000 series and the XPS17 9700 and the Alienware machines have a switch in the bios that allows the GPU direct access to the output ports on each machine. It's called "special-graphics mode". I believe that the laptop screen is still controlled by the Integrated Graphics.

I would certainly be grateful for any further information that anyone discovers as I'm currently looking for a new laptop. Everything that I have found is by implication. Dell doesn't seem to list anything about how this works on their machines and the sales people don't know anything.

XPS17: https://www.dell.com/community/XPS/Xps-17-rtx2060-vr-support/m-p/7629834#M64121

Precision 7000 Series. The very last note on this page shows that. Also the note under HBR3: https://www.dell.com/support/manuals/en-ca/dell-wd19tb-dock/wd19_tb_userguide/display-resolution-table?guid=guid-5558fc88-5c31-4e2c-90be-42359855a1ae&lang=en-us

The Alienware M15 R3 (the one I'm looking at) is rumoured to do it, but I can't find specific reference to it. Still looking. It doesn't appear to be listed in the system setup:
https://www.dell.com/support/m...

Here's the Users Guide, which has lots of GPU info, but not an answer to the specific question as far as I can see:
https://topics-cdn.dell.com/pd...

Cheers,

Hugh