If you want to get some help , please post your full system spec , incl psu rating , how you connecting 2 psu ( what powering what ) what risers are you using , what is your system mem ...
Right now I'm just using 1 psu, it's corsair hx1200. Risers are Mailiya PCIe Dual Chip PCI-E, GPUs are 8gb, system memory 4gb. Anything else?