# Time cost of thread creation

While creating an algorithm, the following question came up:

In uniform cost, what is the time cost of a process that creates a thread?

Is there a difference between creating a thread in a thread pool vs creating a thread in runtime?

I know these questions should be self-explanatory, but I cannot seem to find an answer.

• In most theoretic models, there are no threads at all. Is there any reason to think that such creation is not $O(1)$ in both cases? Are you really asking, "which is faster"? – Raphael May 19 '14 at 18:38