My network actually ran better when my OpnSense was virtualized on a Proxmox server running atop a Dell Optiplex 790 MT from like 2013, than it is currently on a bare metal Sophos SG-135v2.

But that is because the sophos has 8 ports. And all 8 are a separate interface, so to use them as a switch requires bridging 7 of the 8.

And that slows things down tremendously. I really just need an 8 port switch in there, I guess.

The upshot is, the sophos came with rack mounts.