Why does increasing the number of identical parallel operations increases each operation time?

[stevengj]

@lmiq

think the problem can be associated with the fact that if one wants to generate a single sequence of random numbers, all threads will be accessing the same seed sequentially,

That’s not how rand works in Julia; it’s generating “independent” pseudorandom streams (i.e. starting from different seeds) on different processes or threads, so no synchronization is involved.