That was my question, yes. I did not think the drives would be eating much width being that they tend to be silent when not in use. Most, if not all, of my ports on the MB are taken up with peripherals, including a few drives. I can't imagine how they could be killing the card's speeds or causing the problem.
It depends on the card, but if it's maxed out, you might want to consider it. Are there no ports on the motherboard, or is that why you have the pcie card?
edit: It also comes down to not only how many things connected, but also if those devices are active. If they're just external drives, and they aren't actually reading/writing, then they aren't using much bandwidth, if any.
That's about where I had left it, aye. I submitted a ticket and they replied within a few hours to more clearly define what the problem is. I will post their reply here once they give us some better insights.
It could be drivers, or just the fact it's still in beta, or maybe even some Windows setting(?).