[thermaltake madrid 850w how to power 8pin + 4pin CPU ?]

I have a Gigabyte x399 motherboard? it goes with 2 cpu power sockets 8 pin and 4pin. Madrid 850w PSU have only  one 8 pin EPS (4+4) wire.

I connected  it to 8 pin socket on motherboard . Question is how to connect second 4pin CPU power socket? 

Additionally it has 2 red 8pin Pci-e sockets.

Is the 8pin(6+2) pcie different fom 8pin(4+4) cpu (some psu models mark them like  they are the same )? Can i use  wire like that(photo attached), keys on the wire are the same, or do i need some molex to 4pin converter ? Iam a bit confused because of keys, is wiring the same or not?