Keep in mind, though, that if your DoWork function has some large amount of data in it (like, it's looking up each element of the Data list in a large orddict), every process created by pmap will get a _copy_ of that large orddict. Erlang's awesome, but it's not perfect; one of the current VM decisions is that no memory is shared by two processes, so it's sometimes a problem when blindly trying to convert a map to a pmap.