Why there is memory overhead when loading scene asset bundle on ipad mini 1?

Hi,

1. i try to run app on ipad mini 2, ipad air, iphone4 or iphone5

2. scene asset bundle is downloaded

3. scene is loaded, peak is around 160mb

Problem:

1. i try to run app on ipad mini 1

2. scene asset bundle is downloaded

3. scene is loaded, it goes beyond 250mb and crashes.

If I cut out some textures/animations from the scene, then peak in 1st case is around 120mb and on ipad mini 1 is around 220mb.

It seems like there is around 100mb overhead...

Why? Any suggestions? Is there any real big differences between how unity works on ipad mini1 and ipad mini2?

Inb4: the app is 2D and I mainly use sprites