I have 2 identical cards on my board. One seems to draw 75W while other 115W. Why is that?

I have two Gigabyte GTX 1060. In excavator.exe they are both on %100 load but one seems to draw 75W while the other is 115W. Is this something to do with PCI-e x16 and x8 and is this basically a problem?

Maybe what you need are some risers...