cisco001 :
I suggest getting motherboard with 4 RAM slot
Are you getting RX470 second hand?
I think RX 570 faster at same price
Just to reiterate from my first post, the RX 470 and RX570 are both based on the same Polaris 10 GPU. The RX 570 has some incidental tweaks, basically an extra memory state (power saving), but the only difference is that the 14nm LPP process on which their based has been gradually refined over the year since the RX470/480 was launched, so the newer GPUs can run at slightly higher clock speeds. That's it... that's the extent of the difference between RX 470 & 570.
Loads of retailers have stocks of 470s left which some are selling with healthy discounts. It makes sense to clear out old inventory. So OP, like I said, you can basically look at the frequency and cost difference between the cards and make a decision about which one is better value.