So what is problem can be else? Do you have any idea ? Thanks

Hey guys please help, i got this motherboard GIGABYTE GA970 dsp3 and install first red devil rx580 video card after sime job done i was able to mine at 31.5mhs but when i install second card in second slot for videocard i can only hash total 40mhs on both card, I switch them replace them still same problem i was trying find something in bios about PCI Settings or something but tgere is nothing, please help