Can you list the exact model of your memory kit for me? Also does this happen with your system at stock with RAM at 2133MHz?
Can you confirm that you've populated the 8 pin power header on the motherboard?
I notice that your EVGA GTX970 SSC w/ACX2.0+ uses a 8 pin PCIe cable and a 6 pin PCIe cable. Are you using one single PCIe cable to power both connectors? Or are you using two separate PCIe cables to do so? If you're using one cable, please try using two cables for testing.
Since your EVGA supernova 850 G2 850W PSU has a modular design, try alternating between the different VGA connectors to see if that makes a difference.