Like the sibling, I run opnsense. There are other similar things you can run, or maybe just a vanilla Linux / FreeBSD / OpenBSD. I have it installed on an HP E

Like the sibling, I run opnsense. There are other similar things you can run, or maybe just a vanilla Linux / FreeBSD / OpenBSD. I have it installed on an HP EliteDesk 800G2 SFF that my office was going to throw away. It has an i5-6500, 32 GB RAM, two Samsung 840 EVO SSDs and a 2x10Gb Mellanox card. Before the Mellanox, it had an intel 4x1Gb, i350 IIRC. I've run the PC with the intel card connected to a power meter and it was pulling 14-15W while running OPNsense and HomeAssistant, both in dedicated VMs. Some of the dedicated routers may be better than that, but when you factor in the price of the unit, mine isn't too bad, despite the rise in electricity costs here in France. I don't have any other 10 Gb/s machine to test its max performance, but it could run PF with NAT at 2.5 Gb/s without breaking a sweat.