Is rx580 close to gtx 1060 in performance? Cause when i compare the cheapest gtx1060 to the cheapest rx580,rx580 is 60$ more.Is it worth that price?it's a 8gb rx580

The cheapest gtx 1070 8gb is 550$ and rx570 4gb is 310$.And the difference of rx 570 4gb and 8gb is 60$

Fun fact the cheapest rx570 and the cheapest 580 r the exactly the same price.both 8gb and both have versions of 500$+