IOS optimization using time profiler and Core Animation

So I have an app, in which I use custom UIView. There are other UIView, which are subviews of that view. All of them have pan gesture recognizers, so that the user can pan them in the specific fashion. When I test my app using one such view all is well and good, it is all smooth and fps is around 55-60. However, when I add the second one(somewhat smaller then the first one, and kinda inside first one, but not as a subview). The FPS of the outer views drops to 20-30, while the inner one(which is smaller) works in 60 fps. This two views are ABSOLUTELY independent, meaning that interacting with one doesn't affect the other one. In addition to that, I checked running time on the interval of one second, the results are the following: For 1 view: 153ms For 2 views 145ms For 3 views 150ms

The calculations that are performed on each view are ABSOLUTELY identical in complexity. Why does one work smoothly, but when I add the second one it starts to lag, while the execution time stays the same ? I would appreciate if somebody could hint me at how I should debug it.

The most consuming operation according to the Time Profiler is repositioning one of the views:

view.center = newCenter

I simply can't understand why FPS drops 2-3 times, while the running time stays the same. What should I look for ?

UPDATE:

So I found the source of the problem, when one view is inside the frame of the other the whole thing is being constantly redrawn, even though no changes were made to the layout of the inner view. So when I positioned a few of them in different parts of the screen everything was fine, but when I put one "inside" the other things get messed up. Inner one works quickly, while the outer one lags. "Flash updated regions" flag in core animation show that when I interact with outer view, inner view gets updated as well. Any suggestions on what I might need to do, because I need that layout when they are one inside each other. So how can I prevent(lock) other view from redrawing ?

Thank You.