Most Ryzen 395 machines don't have a PCI-e slot for that so you're looking at an extension from an m.2 slot or Thunderbolt (not sure how well that will work, possibly ok at 10Gb). Minisforum has a couple newly announced products, and I think the Framework desktop's motherboard can do it if you put it in a different case, that's about it. Hopefully the next generation has Gen5 PCIe and a few more lanes.
you can use separate network adapter with RoCEv2/RDMA support like Intel E810
Most Ryzen 395 machines don't have a PCI-e slot for that so you're looking at an extension from an m.2 slot or Thunderbolt (not sure how well that will work, possibly ok at 10Gb). Minisforum has a couple newly announced products, and I think the Framework desktop's motherboard can do it if you put it in a different case, that's about it. Hopefully the next generation has Gen5 PCIe and a few more lanes.