Gregory's Server@babble_endanger @thegibson You can get a used Fujitsu Futro for less than 30 USD. That's x86 hardware with low power consumption (~10W), which even has PCIe and SATA connectors. May be significantly cheaper than consistently burning electricity for an old gaming machine.
@toe @TheGibson Thanks, I'll look into it.
I haven't had the Kill-A-Watt plugged in for a while, but I'm running the desktop with just its iGPU and I think it's around 30 W. I say "gaming machine" loosely. It plays Portal 2 at good FPS with the dGPU connected.