Is perspective camera rendrering more efficient than orthographic camera?

I have iPad app with near 70 draw calls (GUI + meshes). If camera is orthographic i have 20 FPS. In perspective - 30 FPS.

Edited. More info:

Perspective camera shows more objects:

38 - 50 draw calls for orthographic camera and

63 - 75 draw calls for perspective one.

Nevertheless, app with perspective camera runs faster:

orth: 17 - 21 FPS depending on the number of objects

pers: 30 FPS stable, sometimes 28.

And, screenshots. orth

pers

Maybe it's the gfx fill rate - the ortho scene is a lot larger - can you draw it smaller to test?