There is no option in Multisim to control multithreading.
If you are having an issue with performance (I'm guessing based on your question), I suggest you contact technical support or can you describe the issue you are having here? If you are having an issue, we want to know about it.
That's what I feared.
Thank you for your reply.
Neverthless It looks me odd that a simulator, that could have lots of benefits from multithreading, yet cannot rely on this opportunity.
It's like going on a balloon in an ultrasonic plane contest.
Despite my 8-core, i feel like I were on a 286.