I need to watch my typing too - I meant to say that the autocorrect makes the post hard to understand. (Autocorrect is EVIL).
A cup and a half is not enough for a GSD pup - they grow so fast, and are high-energy dogs, your pup should get roughly three cups of kibble a day. But that can vary depending on the food you feed and your pup's needs.
Also as other have said, there are some much better foods out there. The puppy feeding section should have some recommendations that you can try.
I got good results from the Wellness brand, and the Dog Food Advisor site gave it good reviews iirc. My dog is currently eating Blue Buffalo, though, cause apparently the Wellness made her smell like fish :-\