And the answer is, you are all right! It depends on the type of pasta, I find egg pasta cooks more quickly, for some reason flavoured pasta ) eg spinach, tomato or mushoom) takes a minute or two longer, the shape - riggatoni with it's thick ridges will take longer than say, spaghetti - plus, you know how you like it. I've been served 'al dente' pasta that wasn't, it just hadn't been cooked enough, to stuff that resembled wallpaper paste because they liked it ultra soft - another answer is, try fresh - toss into boiling salted water, and when it rises to the top, it's cooked.