Whyte punches very hard, certainly hard enough to KO Wilder. Wilder has great power himself and probably punches even harder, but Dillian has a far better chin. Dillian would soak up some early punishment and then Take wilder out with a straight right hand over the top.
I have seen enough of both of them to pick Wilder to win. Wilder has more power and hand speed and a better jab. Wilder hasn't fought the best of opposition but it's certainly beater than the very limited opposition Whyte has faced.