I just got a UHD monitor to try out which is 3840 x 2160. If I tell the game window to take a fixed size of 960x640, and then give it plenty of room to do so, it ends up taking 1440x960 instead. I verified this by taking a screenshot of my computer and measuring in a paint program.
If I click the stats window it also says its running at 960x640. This is pretty concerning since the main purpose of a high rez monitor is to get the game window smaller while testing high rez setups.
Anyone know the deal here?
EDIT i checked iPhone6 + and its the same problem. Its using 1.5x the pixels that it should be (2880x1620).