What is faster - Loading a pickled dictionary object or Loading a JSON file - to a dictionary?

What is faster - Loading a pickled dictionary object or Loading a JSON
file - to a dictionary?

What is faster -
(A) 'Unpickling' (Loading) a pickled dictionary object, using pickle.load
or
(B) Loading a JSON file to a dictionary using simplejson.load
Assume: The pickled object file exists already in case A, and that the
JSON file exists already in case B