Strange behavior when using two GPUs

[slyexe]

You have two cards stacked on each other blowing hot air onto the other card. Not only that but you Motherboard is putting out more power to the PCI-E slots so there is going to be more heat coming from that too. Reference design cards where the heat is blown out the rear of your chassis is the more efficient route. Turn your fans up and remove any backplates on the card which is stacked.