Gigabyte Aorus B550 Master and IOMMU / USB Passthrough

[micro-nerd]

Hello everyone,

 

I recently built my own gaming rig with the Gigabyte Aorus B550 Master & Ryzen 5 5600X. I love my new rig and decided to give Unraid a try (because it seemed like a waste to run just one OS when this box has so much raw capability). I am VERY impressed with Unraid. So far, I have managed to get VMs with full graphics passthrough working fine (my Windows VM is using the RTX 3070 and my macOS VM is using the GT 710).

 

My issue is with IOMMU groupings, but more specifically the Unraid USB flash drive. The Aorus B550 Master has 6 x USB2.0 slots, 6 x USB3.2 slots (included in that is a USB Type C). The IOMMU groups are such that all 6 USB2.0 slots are grouped together (including a 7th one that is theNZXT case that is plugged into the USB header). It seems like such a waste of 5 USB ports that would be useful for things to pass of to my Windows VM. So right now, I have the onboard USB3.2 controller fed to the Mac VM, and I have a cheap Renesas based USB3.0 PCIe card being fed to the Windows VM. Is there anyway of getting the Unraid USB to isolate on it's own, so that I don't waste 5 USB 2.0 ports?

 

The dilemma that I am facing is that I have an ATEM Mini Pro with 4 cameras plugged into the Renesas card in the Windows VM, but when I plug my Logitech C920 into the same card, it does not work (Windows sees the webcam, but black screen). When I boot into my bare metal Windows install, plugging the C920 into one of the USB2.0 ports, the webcam works perfectly fine. It's an issue with competing resources on the USB bus.

 

If I buy one of those cards (like a High Point or Sonnet) with 4 independent multi controllers for the USB, can I assign 1 of those for the Unraid USB, and stub the 3 others to make available in a VM to free up the USB2.0 ports for VM usage?

Edited May 6, 2021 by micro-nerd

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