I was working on an Ethereum 6 GPU open air mining rig.  I originally ordered a Biostar TB250-BTC+ 8 GPU board, but it got lost and never showed up, tried to order another but was backordered for like 3 weeks.  So I picked up an MSI Z270-A PRO in the mean time.  So if you’re curious, this is the hardware I’m using right now.

Memory wise you don’t need that much.  I got a good deal which is why I put in 16GB RAM.  When I started with the first two cards everything worked great, but as a I added more cards I needed to make a few adjustments in the bios.

These are the tweaks I had to make.

When I plugged in the first two video cards the motherboard video stopped working.  First change I had to make was to switch to Integrated Video instead of auto.

Now I’m able to get the on board video again, my next issue was the motherboard would just give a blank screen when powering on.  It flashed like something happened, then have a single underlined cursor in the top left, and would just sit there.  Basically the bios wouldn’t post.

After doing some research, I first downloaded the latest bios, and upgraded.  Just wanted to make sure if there was any issues I had to latest version.  Got that upgraded okay, but still the same problem.

Then I made these 3 changes in Settings > Advanced > PCI Subsystem

Enable 4G Decoding / Crypto Currency Mining

Set PCIe Latency Timer to 96

Set PCIe to Gen 2

After making those changes, rebooted and everything has been working for me.  Hope that gets you up and running also.