That's way, way too high. You need to lower power limit, as others itt have suggested.
That's not the power consumption mate, it's all about the power supply. Actually 6 * P104-100 consume not that much power, as far as I know the TDP is about 180W - 225W, depend on which manufacturer. For me I'm using 1600W PSU for the rig with: 6 P104-100 + 2 P106-100, power limit was set at 80%, so far so good.