Assuming that you are talking about gaming, none of them can give you both. 7700k can give you more performance than 1700x for...lets say X number of years. 1700x will give you little less performance for X+2-3 number of years.
I would say, at this point, 1700 is a better investment. The 1700x does not OC as good as the 1700... http://www.tomshardware.com/reviews/overclocking-amd-ryzen,5011-5.html and after OC they both come arounf the same point.
Assuming that you are talking about gaming, none of them can give you both. 7700k can give you more performance than 1700x for...lets say X number of years. 1700x will give you little less performance for X+2-3 number of years.
I would say, at this point, 1700 is a better investment. The 1700x does not OC as good as the 1700... http://www.tomshardware.com/reviews/overclocking-amd-ryzen,5011-5.html and after OC they both come arounf the same point.