When should you use multithreading? And would multi threading be beneficial if the different threads execute mutually independent tasks?

Question

This were the only two questions I couldn\'t answer in the interview I got rejected from last night.

Answer 1

In general, multithreading is used in cases where execution time is throttled/bottlenecked by the CPU as opposed to other areas such as IO. The second question is really quite subjective to the circumstance. For example if they are mutually independent but both do heavy IO, you might not necessarily get a large gain.