If you are a beginner, I would advise you to study a simpler and more inexpensive solution and you will not break this motherboard by incorrectly connecting the riser in the pci-e x1 connector
https://aliexpress.ru/popular/b75-motherboard-mining.html at $80 this is the perfect beginner kit for 12 GPU,and this motherboard has no problems with bios settings.
The REBTECH is simpler, it doesn't have PCIe_x1 slots, it uses USB connectors instead. There's no need for those flimsy PCIe adapter tabs.
I'd recommend a board that uses USB connectors for PCIe for a dedicated GPU mining rig, but one that can also accomodate a decent CPU for a hybrid rig.
On the other hand I wouldn't recommend a mining board for a newbie, I'd recommend a regular board with lots (up to 6) of PCIe slots. The newer boards
have fewer PCIe and more m.2 so I'd look for an m.2 to 4x PCIe adapter to support more GPUs if necessary.
If you lose interest in mining you can repurpose a regular motherboard. You can't do that with a dedicated mining board.