A question on the screen x1, x2 etc

[Carter07]

As Henrik said, the pixel shader generator doesn't yet produce very optimized shaders so when it will be optimized you'll be able to play at 2x resolution at fullspeed.

This generally is not a problem for desktop (apart some super low end gpus like yours ) but it is for android. Strongest devices can play well at 1x resolution but struggle at 2x resolution in most games, a lot of android devices are gpu limited even at 1x resolution.