Boiling Shrimp

hate to drag up an old thread, but when i searched for boiling shrimp, this was the one that came up.
i know the method to use, I've done them in the past . but I've only done like 20lbs at a time.
this weekend I'm doing like 80lbs. i have a pot big enough to do that much, should i do them all at once or split them up into 2 boils?