I built a server out of mostly used parts I bought on eBay.
Currently (August 2026), I’ve shut down the local LLM experiment and machine zero is running Einstein@home. I have a watt meter between the power supply and the wall, but I don’t have a process in place for tracking electricity usage. I could reset the watt meter and check it after a series of intervals, I just haven’t done that yet, mostly due to not being able to figure out the zany 10-parameter model my electricity provider uses to value electricity.
The CPU to heatsink connection is weak, so it overheats and throttles under load. I replaced the thermal paste, but I don’t think I used enough. Fortunately, the GPU handles heat efficiently and does most of the hard work, so as a whole, the box runs on the hot end of warm without being critical.
I have a smoke detector sitting directly on top of machine zero, though, so that’s a measure of my confidence in the wiring.