What board should I get

[Alexander_96]

Planning on building Ethereum Classic/Ethereum mining rig. Using Ryzen 7 1700, 2 RX 580 8GB when it launches, and i will need at least 16gb RAM. Is there such a mobo yet?

 

[velocityg4]

Doesn't really matter. Ethereum is all about GPU usage. Link speed doesn't even matter. As long as it is getting PCIe x1 or better that is enough. If you wanted you could get a board with seven usable slots total. Ranging from PCIe x1 to PCIe x16. Then use risers to connect a x16 card to a x1 slot.
https://www.amazon.com/Express-Adapter-Extender-Flexible-Extension/dp/B008BZBGPO/ref=sr_1_13?ie=UTF8&qid=1491429411&sr=8-13&keywords=pcie+riser

As for gaming. Just be sure it splits the PCIe lanes for x8/x8. Probably stick with an X370 board as they are meant for multiple cards.

The ASRock X370 Taichi is quite nice.