Noise like beauty is in the eye of the beholder. It depends upon what you set as your standard. I have taken shots like this one at 2500 ISO with a D7000 that NCC saw fit to print in one of their quarterly "leaflets".
The D7100 has even better high ISO performance in my opinion. But as a previous responder has suggested, shoot at 800, 1600, 3200 in various conditions to determine what you find acceptable. Turbo