On a single processor, Will multi-threading increse the speed of the calculation. As we all know that, multi-threading is used for Increasing the User responsiveness and achieved by sepating UI thread and calculation thread. But lets talk about only console application. Will multi-threading increases the speed of the calculation. Do we get culculation result faster when we calculate through multi-threading. 

what about on multi cores, will multi threading increse the speed or not.

Please help me. If you have any material to learn more about threading. please post. 

Edit:
I have been asked a question, At any given time, only one thread is allowed to run on a single core. If so, why people use multithreading in a console application. 

Thanks in advance,
Harsha