Cacio e pepe is ABOUT the pepper... I like black pepper, but I do not like finely ground black pepper, which is what's used in cacio e pepe. So I avoid it.
But if you were cooking the pasta normally, in a lot of water, you'd use two tablespoons of salt, more or less. There isn't any other salt in the recipe, though the cheese is somewhat salty.
But... Who cooks spaghetti for TEN MINUTES?? As Alton says, there's nothing worse than overcooked pasta. I generally use thin spaghetti (spaghettini) and cook them for a little less than 6 minutes. Spaghetti takes 8 minutes. That's if you're using Barilla, or most durum wheat pastas.
I can't imagine what 2 and 3/4 tablespoons of pepper would have tasted like.
It would, unfortunately, have tasted like nearly 3 tablespoons of pepper. Many, many years ago--in the early 80s--the brother of an Italian friend got married. So Grazia invited him and his wife to Florence, where she and her boyfriend decided to host a dinner for them.
For reasons I don't recall, she chose a restaurant none of us had ever been to in Impruneta, just outside Florence. It seemed the chef had won an award decades before for his signature pasta dish, which had a name I forget involving pepper.
God. It tasted as if he'd just thrown in a pound of finely ground pepper. That was the ONLY thing it tasted of...