So I'm using an EVGA SuperNOVA 850 T2 and the MVE(Maximus V Extreme) has 3 ATX power connectors, 24, 8, and 4. The PSU has 2 x EPS/ATX12V 8(4+4)Pin outputs but the cables don't match up with the 8-in header on the mobo. I can use the split 4+4 connector but only use one of the 4-pin in the 8-pin header. The header pin doesn't match the cables. Is my PSU not "beefy" enough and therefore doesn't come with the proper cables or am I missing something here? Any help is much appreciated.

I linked the mobo manual page here, page 1-48.
https://dlcdnets.asus.com/pub/ASUS/mb/LGA1155/MAXIMUS_V_EXTREME/E7627_Maximus_V_Extreme.pdf

Thanks,
Greg