Thanks for the reply!
Probably 30 minutes or so; I know that many people like to leave it running for 24 hours or so, but I don't have the time at the moment. It seemed that the temperatures didn't climb at all over the elapsed time, so should I run it for a SUPER long time to see for sure if temperatures will climb? Because it appears to be very stable.
EDIT: I just did another stress test for 1 hour, and the temps stayed constant and the same as posted before.