Unity 5 ipad2 display sprites from 2048 texture

I try to understand how 2048x2048 textures(2D atlases) can be used on IPad2.
I create an empty project in Unity5, add to two atlases with same sprites (the first atlas 1024x1024 and the second is 2048x2048) and get different results, as you can see on the screenshots (the sprites from the bigger texture have bad quality).

Moreover, the same project in Unity4 works properly. All settings are same. Max texture size in import settings is 2048 (tried also 4096). Quallity is fantastic.

May be I look over some settings. What settings can impact on big texture quality?

Unity does not support texture 5 2048?