Home server with 13Watt base draw

TL;DR

If you want a server that has a base power draw of just 13 watts, use :

• Intel i5-10400F (i5-10400 should also be fine)
• Asus B560M Pro motherboard
• Corsair Platinum SF 450 PSU
• 32 gbs of sane DDR RAM
• a single SSD for the OS disk
• no GPU (the B560M will boot fine to Proxmox with no GPU)
• Proxmox 7 as OS
• Measured at the wall using a generic killawatt-type reader

The long version

Previous Build - 60W

With the world and energy prices going crackers in 2022, I re-evaluated my homelab situation to determine if I could reduce its power consumption any. My server until now pulled about 60 watts on average, and at its core was a Ryzen 5 1600 CPU and Asrock x370M Pro4 motherboard. Both where leftovers from other system upgrades, so they were not picked for ideal power consumption. For a PSU I used a Corsair Platinum SF 450 - this PSU was picked after testing a few others, and I think it pretty efficient at low draws.

For an operating system I used Proxmox 6 and removed the GPU - even a low spec GPU like a GT 730 adds about 7W constant draw to a system, and you don't need screen output for Proxmox. Note that not all motherboards will POST with the GPU removed, but the Asrock x370M does.

With no disks or VM guests, the above system had a starting power draw of about 24W, which I figured was passable. Once I added VMs, containers, just one spinning disk and a few SSDs, my base draw almost tripled and no amount of optimizing or configuring helped.

New Server - 33W

A 60W draw might seem trivial if you're living in a country made out of electrons, like the USA, but here in Europe, especially Denmark where I live, electricity famously comes from free and abundant sources like the wind, so naturally it costs ten times more. After seeing Wolfgang's Channel's low power draw server build video I was curious to see if I could recreate the results he got from Intel-based systems. Turns out I could.

For a CPU I went with a i5-10400F, as 6 cores/12 threads are enough for any system that's meant to be low draw. Even a modest CPU like this will clock up a high power bill if it's constantly busy, and I feel this is something that many people get wrong with low power builds - it's not just about picking the right hardware, but also tuning the work you're doing on that hardware.

For a motherboard I took an Asus B560M Pro, this board is clearly aimed at business users, without any of the usual "gamer" trappings like RGB, overclocking or triple redundant military-grade capacitors. It even seems to have several additional power saving options in the BIOS that I haven't seen on other systems, but it's hard to confirm if these make a significant difference.

I threw in 32 gigs of stock DDR4 RAM with no fancy clockings, installed Proxmox 7 on a single SSD (no RAID1 redundancy, I'll explain in a later post), and reused the Corsair Platinum SF 450. I also installed powertop and used its autotune function, and removed the GPU yet again (can confirm that Asus B560M Pro also POSTS without a GPU in it). I measured power draw with a generic Killawatt-type power reader at the wall. The base draw of this system is … 13 watts! That is pretty low, but the best is yet to come.

Once I had provisioned my server for actual work - added in several mechanical disks, SSDs, guest VMS, containers - my average power draw is 33W. This machine is doing exactly the same work my previous 60W system did, just at half the draw. I've been a loyal AMD user since the Ryzen line launched, but Intel definitely deserves kudos on its power optimization.

Stay tuned for a later post about how and why I configured my home server.