It only shows the 7 of them. You just set them all to gen1 and then save and restart. Then first try 8 cards. Login let all the drives load. Shut down, add the 9th. I had to skip one of the PCIe slots so my 9th is plugged into my 10th port. I had the same trouble you guys are having, even crashed the damn thing a few times and had to unplug the cards. First time only 6 would work. I did do as was suggested and try to install the other catalyst driver. Now running w/ 9 cards. All AMD RX580.

Anyhow, thats pretty much all I did after having the same problems. The steps all were posted above I think.