스택오버플로우에 있는 답변이다.
병렬소팅은 스레드를 사용하여 대량의 데이터 처리시에 더욱 효과적이란다.
Parallel sort uses threading. It's faster when there are a lot of elements. The overhead for parallelization becomes tolerably small on larger arrays, but it is too big for smaller ones.
Take a look at this table (of course, the results depend on the CPU, etc):
답변 : http://stackoverflow.com/questions/17328077/difference-between-arrays-sort-and-arrays-parallelsort