I'm not into gaming, but as I understand it there are two processing issues related to display resolution and battery use.
1: In the case of a high density display set to high density native resolution, the game needs to:
A: Compute the color of each pixel at native resolution.
B: Pass that information to the display driver that will them process that information and light each native resolution pixel properly.
2: In the case of a higher density display set to lower density resolution, the game needs to :
A: Compute the color of each lower density pixel. (Not each native
Since there are lower number of pixels being computed, so less power is used for these computation than for native high resolution.
B: Pass that information to the display driver that will upscale them process (pixel, doubling. interpolation, antialiasing, etc.
This an extra step requiring processing power.
C: Display driver then passes appropriate information to each actual pixel. I assume that this is the same amount of power as case 1. B.
D: The game may work better, but does this save energy? I do not know.
3. In the case of a standard density display, the game needs to:
A: Compute the color of each pixel. Less pixels than a high density display = less energy than a higher density display.
B: Pass that information to the display driver that will them process that information and light each pixel properly.
Less pixels than a high density display = less energy than a higher density display.
Maybe someone how understands this better can give a definitive answer.
I don't know how VR will look. I will go by a T-Mobile store and check it out in a few days.