My homelab power budget, measured for a month

October 28, 2026 · #homelab #hardware

I finally put a smart plug in front of the whole rack and left it alone for thirty days. The short version: the mini PCs are not the problem, the old NAS is.

What is in the rack

  • Three used mini PCs (i5-8500T) running Proxmox
  • A four-bay NAS from 2017
  • An 8-port managed switch and the ISP router

Numbers

Idle draw for the cluster was 31 W, the NAS alone sat at 38 W with disks spinning, and the switch added 9 W. Over the month that came to 57 kWh. Spinning the NAS disks down after 20 minutes saved about 11 W on average, which is more than every tweak I made to the cluster combined.

hdparm -S 240 /dev/sd[a-d]   # 20 minutes
powertop --auto-tune

Next step is replacing the NAS with two large SSDs in one of the mini PCs. I will post numbers when it happens.

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