Since this board designed with a lot of PCIe slot, you need middle-end or higher LGA 1151 Processor for whatever algorithms. This is about overall performance, mid-end /hi-end Processor will handle all of your GPU's. Another thing, I agree with this:
memory 8gb, hard disk = ssd 120gb minimum.
I feel like a lot of builders miss this in there design and budget.
I for one didn't budget for the cost of 1151 cpus and am at a bit of a standstill gathering parts deciding which processor to get.
They are far more expensive then I thought.