Unity Terrain on Android performance

I am having issue with Terrain on Android. I tested empty scene with Terrain on Android, running at 60 fps with few basic objects, turning on very basic terrain ( no details, 200 size, one texture ) drops the framerate down to 30 fps. 30 frames drop for basic terrain seems crazy. Can someone please let me know if there is anything i can do about it ?

Thanks
Luke

Use Custom (Mobile) material on terrain and lower settings of terrain. With this I got fps back to 55-60 fps.