multiprocessing

[ian]

I have 2 functions to run in series and it takes 2 minutes in total to finish (on Windows 10 x64, python 3.6 x64)
Then I try to run them concurrently as below and want to finish faster. But it takes 4 minutes in total. what is wrong? Thanks

p1 = multiprocessing.Process(update1)
p2 = multiprocessing.Process(update2)
p1.start()
p2.start()
p1.join()
p2.join()