I’ve been using Raspberry PI’s for various experiments at home. A few years ago a bought an Intel NUC, and I’ve been running Windows 10 Pro with Hyper-V on it.
To be honest, I wasn’t very happy about the performance of my raspberry pi’s anymore, and I was quiet happy about what I could do with the NUC (all while my wife uses it to watch TV). But I also found the NUC to be a bit expensive for fire and forget experiments.
I then stumbled upon the HP T620 Thin client. It bundled everything I wanted for a cheap (second hand on ebay, of course) price. It has an AMD x86_64 processor onboard, 4GB of RAM and 16GB of storage.
At that price level I didn’t expect to much from it from the performance viewpoint, but I was really impressed. I’m currently running an OPNsense router from it, completely with VPN tunnels and intrusion detection systems. It does it without any problems. Only downside for this scenario is the single Ethernet port. (I planned to try to replace the wireless interface, which is not supported by OPNsense with an Ethernet interface, but haven’t gotten to it.) However, this can easily be solved by using multiple VLANs at that one port.
So if you are looking for cheap second hand systems for your homelab that don’t consume to much power, look this one up on eBay!
PS: My raspberry pi’s which have been relieved from duty have already been claimed again to function as VPN endpoints/routers. Maybe more on that later…