Tested on Experimental 0.51.125504
I am forced to test it with the integrated display only right now, cause I am on a road trip [gaming notebook FTW ;)]. No second display connected to HDMI.
No matter what I write into the configuration file ("DayZ.cfg") to the line "adapter", the game uses the integrated (weak) Intel HD 4600 graphics.
I tried to run DayZ Experimental in windowed mode, too. No success with integrated monitor only. DayZ refuses to use the GTX.
Hardware configuration:
Like I said above, the notebook-display is hardware-connected to the integrated graphics (Intel HD4600). The GTX has the HDMI-connection and is able to "stream it's signal" trough the integrated graphics to the notebook-display. Just like in every gaming notebook with a similar configuration.
All other games are working. I had some similar issues in "Arma 3" some stable updates ago.
Regards,
Cedrick