8 mo. ago • 100%

Optimize power consumption

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

55 comments

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.

12
- 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
  
  0
  
  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.
  
  5
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.

5
- I guess I’ll do this if I don’t find a way to reduce the power consumption
  
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  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.
  
  6
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

5
- Thanks that would be cool. Also if you can tell me if this is a NUC or something larger.
  
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  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.
  
  4
  
  It is a beelink mini s12 pro https://www.bee-link.com/beelink-mini-s12-pro-n100-mini-pc-clone-1
  
  2
  
  I'm running a n100 16gb with a 256ssd, 4vms and 4 docker images, it's pulling 7-9w.
  
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  So pc is consuming 13W, this is with one nvme + one SSD, pic at 30w for a few seconds at boot.
  
  2
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.

5
- you can also do this in the OS, depending on your hardware it might be more reliable.
  
  2
- I have checked but I haven’t seen anything about power. By any chances, do you know in what category it may be?
  
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  I don’t know. I think that would depend on the BIOS.
  
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  it depends on the operating system you are using
  
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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.

5
- 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 😕
  
  2
  
  I never really tested it with 3.5" HDDs, but a google search makes it sound like they might be closer to 10W each.
  
  3
  
  My guess would be 25W from disks, 10W from CPU+RAM+MBO and 10W waste from PSU. Just a guess as I said
  
  1
- 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.
  
  1
  
  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.
  
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  My server use about the same power no matter if its idle or under full load, so I dont think drive speed makes any difference. My SSDs use much less than my HDD anyway
  
  1
- 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?
  
  0
  
  They use practically nothing when idle, but it spikes up dramatically under heavy load.
  
  Still much less on average than a HDD that uses 5-10W even when idle and spun up.
  
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  In my limited testing 2.5 HDD uses the least power, and SATA SSDs are slightly worse than those, but I guess it also depends on the model.
  
  2
Another way of reducing your overall power consumption: Do you need a NAS to be on 24/7?

My NAS is a NAS - just storage. It comes on and spins the 5x HDDs for a few hours in the day then shuts down. It's a NAS, I don't need to access my files at night when I'm asleep.

My VM host is a low power box with passive cooling which uses a SSD and runs my (mostly idle) VMs 24/7 for a few Watts.

So, maybe splitting up your requirements might save some power?

3
- I planned to share it with my family. As I won’t be the only user, this is not ideal. Besides I run automatic backup and planned to also store them in the NAS. So again if it’s off half the time, this is not ideal.
  
  2
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!

2
- Unfortunately this is idling after boot. While booting it jumps to 70W and I haven’t seen it go below 45W idling…
  
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  Guess it's time to disconnect some hardware and test power consumption.
  
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What kind of PSU are you using?

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- I’m using an EVGA 500 W1
  
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  EVGA 500 W1
  
  That is a 500W PSU, no? That is vastly oversized and therefore inefficient for low power applications.
  
  2

Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:

Fewer Letters	More Letters
LXC	Linux Containers
NAS	Network-Attached Storage
NUC	Next Unit of Computing brand of Intel small computers
NVMe	Non-Volatile Memory Express interface for mass storage
PCIe	Peripheral Component Interconnect Express
PSU	Power Supply Unit
SATA	Serial AT Attachment interface for mass storage
SSD	Solid State Drive mass storage

8 acronyms in this thread; the most compressed thread commented on today has 6 acronyms.

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