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?
See if you can set the max power of the CPU in the BIOS.
It’s really strange for an N100 system to be drawing that much power, so maybe you have some really hungry SSDs or HDDs.
you can also do this in the OS, depending on your hardware it might be more reliable.
I have checked but I haven’t seen anything about power. By any chances, do you know in what category it may be?
Monitor CPU usage and frequencies to ensure CPU is throttling down properly. Then start unplugging hard drives, ram, nic cable to see how they affect power usage. Servethehome shows an N305 idling around 10w in a minipc without HDDs.
I guess I’ll do this if I don’t find a way to reduce the power consumption
Troubleshooting can be difficult. I’ll only say you’ll save yourself alot of time and energy by establishing a baseline for power usage with just the essential components necessary for boot to see what you’re working with. Then you can make better informed decisions.
Is that 45w a continuous draw, or is that from something that measured it while booting?
I have a small form factor Dell Optiplex with 1 NVME for the OS (Proxmox), and 3 drives (2.5" spinning disk), that idles at 10-20w. Running VM’s pushes that up to 40-50w.
And that’s still about 60-70w less than the desktop I’ve been running as a file server!
Unfortunately this is idling after boot. While booting it jumps to 70W and I haven’t seen it go below 45W idling…
You’re not going to see similar power levels to those ARM devices. A massive part will be the drives, 3.5" drives take between 6 and 10W per drive while running.
I’m going to try to unplug these. But even if I remove 20W from the 2 HDDs, there are still 25W which seem a lot
You’re building a machine from parts. Different Mainboard, PSU, CPU and drive combinations. No real way for a system manufacturer to optimize for a specific use case and power target.
The full ATX PSU alone has a widely variable efficiency, and often not down in the low double digit power areas.
Do also have a n100 processor running proxmox with 3 VM. Can’t try right now but can come back in a few days to let you know how much power it draws
Thanks that would be cool. Also if you can tell me if this is a NUC or something larger.
I’m not the other user, but this is my NUC running proxmox with 2 VMs and 2 LXCs. Running with an old i3, 16gb ram and a single 1tb NVME, no mechanical HDDs, and a few USB peripherals like a ZigBee dongle.
For power consumption, NVMe drives use quite a lot of power, especially PCIe 4.0 ones. About 5W each during use.
3.5" HDD (especially 7200rpm or more) also consume significantly more than 2.5" 5400rpm HDDs that are optimized for low power (the latter use about 1W during use).
SATA SSDs fall somewhere in the middle.
How does that work out in terms of energy consumption though?
If NVMe is at least 10x faster, but consumes 5x more power, it will use less energy to read or write the same amount of data overall.
To answer that question one would need to dive deeply into idle vs. in active use power consumption. It’s not like a NAS gets turned off when not in use.
I’m surprised to hear NVMe us that much power - I had no idea, and just assumed they used very little.
It sounds like from a power perspective that 2.5" is better, and SSD is lowest power?
Thanks. So If I take 5W a disk, I may have 20W just from the disks.
There are still 25W remaining. For a low power CPU that looks like a lot 😕
I never really tested it with 3.5" HDDs, but a google search makes it sound like they might be closer to 10W each.
What kind of PSU are you using?
I’m using an EVGA 500 W1
EVGA 500 W1
That is a 500W PSU, no? That is vastly oversized and therefore inefficient for low power applications.
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?
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.
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.
