Optimize power consumption

Kwa@derpzilla.net to Selfhosted@lemmy.world – 38 points –

So I have finally built my NAS. I used an N100 CPU because I saw it has low power consumption.

Right now I have 2 NVMe SSDs and 2 HDDs. I have installed proxmox on the 2 SSDs as RAID1. I have not partitioned the HDDs yet, they are just plugged in and powered on.

Just booting into proxmox, without any VMs or containers running, I am pulling 45W from the wall. This looks super high to me, and I’m afraid that starting to use the HDDs and running some VMs may double this…

I don’t have much references, but I have an Odroid with an external self-powered HDD, it is using 5W. I have a raspberry pi 4 with an external HDD, the raspberry is pulling 3W and the HDD 3W.

With these data, I was thinking I wouldn’t go over 20W. 45W is enormous and not something I can run 24/7, kind of a fail for a NAS…

Have I done something wrong or is it just how much it’s supposed to pull?

Edit: I have come across powertop. Using the auto tune, I was able to drop to 33-35W. I have unplugged the HDDs and dropped to 22W. I guess I cannot go lower, this may be because of the PSU or the 2 NVMe

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I don’t know much about hardware. I used these suggestions: https://forums.serverbuilds.net/t/guide-nas-killer-6-0-ddr4-is-finally-cheap/13956

I built a NAS where I can put 6 HDDs, there are enough plugs on the PSU.

Do you think the PSU is the issue?

I was testing around 5 different PSUs (500-750W silver/gold) on the same machine and I was reading 20 - 35W from the wall. So yeah I think PSU plays a big role. They are most efficient at around half of the rated load and we are using them at <10%.

Listen to this guy! Spot on. When I built my server I spent more time researching and paying for the PSU more than any other single part. Ended up with a Seasonic PRIME FANLESS PX-450. Server idles around 25W with a ryzen 5600g and 40TB of storage.

While more expensive, a fanless one is probably a good idea as it will be optimized to avoid excess heat, which is incidently the same as inefficient power consumption for PSUs.

Indeed, this seems to be the issue!

I’ve checked the PX-450 but it seems to be out of stock…

I’ll do more searches about PSU, thanks!

Have a look at this: https://www.youtube.com/watch?v=TPSuCbS-4P0

TL:DR; The 'rating' of a PSU (ie; Gold, Platinum), has very little to do with efficiency at lower power like 20-40W, and this person has compiled a list of tests for a bunch of models to show which ones are good at low power.

This is amazing, thank you!

And now this confirms that my current PSU is terrible…

Recommendations from such "Homelab" sites are generally not sound advise for people trying to optimize power consumption. They will happily recommend "server grade" hardware that will use hundreds of Watts easily.

While I think the PSU contributes to the problem, it is probably a set of different factors that all drive up the consumption.

Low power regular desktop PSUs are a bit hard to find on the consumer market as there is no demand for them, but you could look into PicoPSUs with an external power-brick.