[zrail]

I just built a relatively decked out router from eBay and Amazon parts for less than $300.

- used HP Elitedesk 800 G3 SFF (4 core i5-6500, 8GB ram, 240gb SSD, 4x PCIe slots) $170 shipped

- 2x new dual 2.5Gbe PCIe cards $40 each

- 1x used quad port Internet gigabit $30 shipped

So for $280 I have a machine that will route at 2.5Gbe for a few machines and gigabit for the rest of my network while using about 25 watts. If you don't need that many ports you can cut the cost down considerably with a smaller machine like a Prodesk 400 or 600.

I'm using VyOS but OpenWRT, Untangle, OPNsense or Sophos Home would also be perfectly fine choices.

[blibble]

I am very much interested in building my own router in a similar way, but 25W is still about 5x as much power as something like a mikrotik

[adrian_b]

I am using an older Intel NUC with a Coffee Lake U CPU, together with 4 USB Ethernet adapters, to increase the number of Ethernet ports to 5.

The measured average power over 24 hours is around 12 to 13 W. The idle power is under 10 W and the maximum power consumption can be up to 60 W, but even a large number of active network services, e.g. firewall, e-mail server, Web server and Web proxy, DNS server and DNS proxy, NTP server and so on, require just a power consumption not much above the idle level.

I assume that a NUC-like computer with a Jasper Lake CPU should have an average power consumption under 10 W. At least with Intel or AMD CPUs and associated peripherals you do not have to worry about software compatibility.

[zrail]

Sure. There are plenty of platforms you can start with that use less power. For the record I haven't actually measured it, that's just a guess. I'll throw it on a power monitor sometime and check.