guys iam newbie about mining and started to build a rig, i wanna buy some sapphire cards and iam little confused is it worth to give an extra 35 $ for Sapphire Pulse Amd Radeon  RX 580 8G OC 256 Bit GDDR5  11265-05-20G
or does is it make sense to buy  Sapphire Pulse AMD Radeon RX570 8GB 256Bit GDDR5 Lite 11266-75-20G

what i see is the clock speed s about rx 580 pulse is  100 mhz higher than rx 570 pulse  ,how much difference does is it  make in hashrates ,
 , whats the real deal about this cards ,can anybody help who know about this  cards  ...   thanks