Efficient and quiet: power, cooling and backup power

A server runs day and night. That makes power consumption, noise and safety matter a lot. With a few choices it stays cheap, quiet and reliable.

Measure to know

Buy an inexpensive plug-in power meter (energy meter) and measure what your server actually uses, at idle and under load. The number on the power supply is a maximum, not what you use. Enter the consumption in our power cost calculator and you’ll see what it costs per year. Smart plugs with metering do the same thing and show it in Home Assistant.

Running more efficiently

Choose efficient hardware. A mini PC or Raspberry Pi uses much less than an old desktop. See the mini PC guide.
Turn on power saving in the BIOS. Look for “C-states”, “ASPM” and an efficient power profile. Check your board’s manual.
Let hard drives sleep when they’re not being used. On some NAS systems you can configure that; on Linux it’s possible with hdparm.
Remove what you don’t use: extra cards, a graphics card that does nothing and unused USB devices.
On Linux you can use powertop to see where the consumption is. Try it out carefully first; some settings can turn off devices unexpectedly.

Noise and cooling

Hard drives are the biggest source of noise. An SSD is silent. Mount drives on rubber or in a dampened enclosure.
Large, slow fans make less noise than small, fast ones. A 120 mm fan is noticeably quieter than a 40 mm.
Ensure airflow. Don’t put your server in a closed cabinet and not in a warm spot. Heat shortens the lifespan of drives. Keep them preferably below 45 degrees.
Dust is the enemy: clean your server carefully every six months with compressed air.

Backup power (UPS)

A power outage can damage drives and files. A UPS keeps your server running for a while and gives it time to shut down cleanly.

Choose by wattage, not just VA. Add up the consumption of everything you connect (server, switch, modem) and choose a UPS that can handle that comfortably, with room to spare.
Line-interactive is a good choice for home use. For sensitive equipment, a UPS with a pure sine wave is a plus.
Runtime: a home UPS often bridges only 5 to 20 minutes. That’s enough to shut down. Calculate it with our UPS runtime tool.
Automatic shutdown: connect the UPS with USB to your server and use NUT (Network UPS Tools), so it turns itself off before the battery runs out.
Batteries wear out: replace them after three to five years.

Surge protection

Good surge protection protects against spikes, for example during thunderstorms. A UPS often provides that too. During severe storms, it’s better to unplug everything.