How to diagnose unknown Profiler OVERHEAD spike (iOS)

Hello guys.
I’ve been profiling my game for quite some time now to see what causes the sudden framedrop and I’ve noticed that there is a big spike on Profiler but unfortunately its all atributed to overhead (running unity 4.6.3)
Are there any ways to break down the other section or force more information for that particular spike?
I can’t really try and fix this if I don’t know whats causing it. (I’ve also tried using Deep Profiling)

Hi, try selecting the spike frame in the profiler then sort by Calls, the first entry is likely to be the main cause of the spike. (overhead is what unity does on its side to run the game, ie. if you have a method called 1000 times it will cause an overhead spike caused by all the processing in background on top the actual method execution cost)