According to Betty Crocker, spaghetti noodles require eight to ten minutes to cook. Cooking times are based on an al dente preference, or slightly under-cooked texture.
Spaghetti noodles are usually dried; however, it is important to keep in mind that fresh pasta cooks faster than dried. Alternatively, some consumers may prefer a softer texture, so you may wish to cook pasta for a few minutes longer. The best method to find your preferred cooking time is to use the original cooking guidelines stated above and occasionally taste test the noodles until you have obtained the desired texture for you or your dining company.