Heyo!

So im fairly new to mining but im in the process of building a 12 gpu rig on the Asrock H110 Pro BTC+.
However i've come across a ton of contradicting information so far.

So theres 2 molex connectors on the board itself, i guess to provide juice to the pci-e ports and i've read some posts saying that i should not use powered risers because of this... I highly doubt thats the case, but thats why I'm here asking you guys.

Apart from that, I'll be using 3 different PSU's to power my 12 Sapphire RX580 Pulse 8GB and the risers. Got those layin around aswell as just enough cables.
My question regarding this is the following: Some people said I will need to connect all the risers to the main PSU which powers the mainboard itself, while others said it's important to have each riser powered by the same PSU that powers the GPU connected to it. Now I'm confused, since I've found multiple contradicting infos and I have no clue what to believe... Does it simply not matter or does anyone in here actually know?

btw my PSUs are: EVGA 1600W G2, 2x EVGA 1000W P2 and the risers are: 5x Molex powered and 10x 6pin powered

Hope you guys can help me out!

Cheers!