I have two same GPU Gigabyte rx580 Gaming 8GB  bought 2 weak ago.  why I get different hash rate ?
Can there be a problem in expansion slots? Because GPU0 is in 16x and the second GPU1 is in 4x ?

Did anyone have same problem?
  
GPU0 30+  30.200~3500 +

GPU1 29+  29,200~29,400 max

M/B  ASUS PRIME Z270-P  

https://s10.postimg.org/609r44p2t/samegpu.jpg