One Id app. 8-12 h
50 id's app. 500h = app. 20 days which is 20 times longer then the actual computation since there will be more of such simulations i think a better solution would be preferable. Unfortunately i cannot temper with the simulation part since i have no source , but even if i did i wouldn't do it since there are a lot of heuristics involved which i honestly don't understand.
Re^4: Counter - number of tags per interval