Support for PCIe passthrough on motherboards varies; check specifications for your model.
Support for PCIe passthrough on motherboards varies; check specifications for your model.
Back story: My goal is setting up a workstation with strong virtualization capabilities. Passing through a USB controller to a guest is essential, so I need assurance that the motherboard can handle PCIe passthrough—possibly via IOMMU on the AMD side, or just the CPU. I assume only one PCIe slot connects directly to the CPU, while others link to an external controller. Would those remaining slots also need passthrough support from the board? And should I consider using an X570 processor for virtualization purposes?
Ensure both components back up the information. A board should isolate the PCIe device within its own IOMMU zone, which depends on the specific model. B550 and X570 allow splitting the X16 from the CPU to two X8s, making that a likely optimal choice. Check user reviews for details, as specifications can differ. What operating system are you using? Is a GPU also being used?
Both options are necessary. The X570 boards offer a more organized IOMMU layout, making pass-through easier. For VFIO tasks, you'll need an X8 or X8 PCIe board with an X570 chipset. This typically costs around $250 for the motherboard. Still, there are some boards worth considering if they outperform others.
no manufacturer has mentioned support for iommu yet. you can check reviews or forums to confirm. for your rigs—x570 auros pro, 5800x, and gygabyte rx 6400—ubuntu is likely, but qbes os and arch-based distros are also viable. it probably doesn’t matter much if the gpu passes a pcie, as long as it works with your system.
Looking for ways to verify compatibility? No brand has mentioned iommu support in their documentation. Concerned about potential issues before buying. Updated June 5, 2022 – added details by itai
Unfortunately, my options are mostly gigabytes and ASUS... that's really surprising! The tension is really holding me back...
I'm not very familiar with ASUS and Gigabyte boards. I currently have an X570 Master running Linux, and I can set up a distribution to check how the IOMMU groups are arranged if you'd like. That still seems like a costly decision. Sorry for missing it—I got sidetracked. GPU passthrough is usually the only practical option. Network cards or USB cards might make sense in some cases, but generally the virtualized setup works well enough.
Sure, I get it. At that stage I could just secure the NUC with a zip tie. But thanks for the support! I'm choosing the X570 Aorus Pro and will let you know what happens.