MOX idle consumption

MOX hardware
1

Hi everybody,
I was interested in MOX consumption, especially the idle consumption because that is what my router is doing ~95% of the time. I found no numbers, so I measured it myself and I am sharing the results for the benefit of Turris community:

A: 2.6W - microcomputer, the version with 1GB RAM
B: 0.0W - mPCIe slot, without mPCIe card
C: 0.5W - 4xLAN, each connected LAN appends roughly 0.1W
E: 1.2W - 8xLAN, each connected LAN appends roughly 0.1W
F: 1.1W - 4xUSB, no connected devices
G: 1.1W - mPCIe slot, without mPCIe card

For various combinations of modules, just sum their consumptions. A+E+C was the only combination I found, deviating a little bit, resulting in 4.5W instead of predicted 4.3W. Additional 0.2W is probably taken by E module that needs to establish high-speed data link with module C. All measurements was made with fully booted TurrisOS with reset to factory defaults and disabled updates, to make sure it is idle.

Consumption of add-ons:

WiFi SDIO

  • disabled - 0.1W
  • 5GHz network - 0.8W
  • 2.4GHz network - 0.5-0.6W

WiFi mPCIe - WLE900VX

  • disabled - 0.4W
  • 5GHz network - 1.6W
  • 2.4GHz network - 1.2-1.3W

SATA mPCIe card - Delock MiniPCIe 2xSATA 6Gb/s

  • no disk connected - 0.9W
  • 1 disk connected - 2.1W (0.9W card + 1.2W spinning disk)

Disk Seagate BarraCuda 5TB (ST5000LM000) + ICY BOX USB/SATA adapter (IB-AC6031-U3)

  • spinning disk - 1.6W
  • stopped disk - 0.7W
  • spinning disk itself (without adapter consumption) - 1.2W
  • various USB/SATA adapters might have different consumptions

Ethernet measurements:
I already wrote that connected LAN port (no traffic) takes about 0.1W (I do not have means to measure it more precisely). I was using short LAN cable. However, I found huge variations of measured values. It seems that 0.1W is the value for high quality devices, like Dell laptops, connected to Turris. Other devices, surprisingly including old HP Elitebook made it 0.6W when connected to the port. The same for ethernet port on my Gigabyte motherboard in my desktop computer. A Dell docking station when connected to Turris LAN port, was consuming 0.6W until I switched on my laptop. I am suspicious that there is a kind of power-save mode for ethernet link and not all devices use it properly. So, each LAN cable plugged into your Turris might cost 0.1 or even 0.6W.

Finally, one warning: No guarantee that the consumption will not vary between hardware revisions and software updates. The numbers are provided ā€œas isā€, just as I measured them, mostly January 2022.

In conclusion, if you fight for low consumption to save your money and the nature, A+B + WiFi mPCIe will give you 4.2W with 5GHz WiFi and all the power of Turris. Additional 0.7W for sleeping disk drive will turn your Turris into NAS provided that you will not make it spinning most of the time. Ethernet is good, but with C module it might push you up by 0.5+(4x0.6), e.g. 0.9 to 2.9W. SDIO WiFi seems more power-wise, but you can find info about some difficulties with it on this forum.

Edit: Typos.

14 Likes
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thank you for this great job!

1GB :wink:

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Fantasticā€¦ thank you for that. Just out of curiosity, how did you manage to do measurements with such level of details?
I have just bought a raspberry Pi hat to do some energy measurements around the houseā€¦ my MOX is on the list so I will publish results once I have completed the tests. But it will only be the overall consumption at the mains, inclusing the losses at power supply (I will disable wifi to check the difference, at least).

4

Also very interesting that ethernet controller does use power even with no devices connected.
And I would expected mush higher consumption for mechanical hard driveā€¦

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You are welcomed! Thanks for this 1MB correction :slight_smile: . Text updated.

6

I bought a consumption meter. Just pay attention to the precision of the device. Many meters stops measuring bellow 5W. I bought the one that can measure 0.1W. Then, you need much of patience and experiment with your hardware to understand it and to measure it properly. During the process, you might need to re-measure everything again as a new unexpected knowledge about the hardware (and software) suddenly appears :-).

Yes. It is like with a processor. It consumes power even if it does nothing. You have to keep clocks, bus, timers, interrupt logic, etc. Well designed devices consume much less power when idle.

Me too contrary to the results :-). These 2.5" disks are designed even for laptops, so just spinning them is quite power efficient. But peak consumption is written on them: 5V and 0.85A, e.g. 4.25W.

Edit: Added more details.

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First: Great measurements, thanks.

You sure your dell laptops got gigabit link? My measurements of various network devices show that one gigabit link costs from about 0.5W on newest devices to about 2W on bad/old ones. Confirmed that MOX consumption goes up by about 1W (2x 0.5W) when I connect two ports together.

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Nice to hear that your findings confirm not negligible consumption of LAN ports.

Concerning gigabit link - I never said I have gigabit LAN port. But if you would ask me what kind of ports it was, lspci gives me this info: ā€œEthernet controller: Intel Corporation 82579LM Gigabit Network Connection (Lewisville) (rev 04)ā€. So, I expect it is, surprisingly for me, gigabit port :-).

Interesting that you measured such higher consumption (e.g. 0.5 to 2.0W) while myself 0.1 to 0.6W per used port. Seems like vendor or device makes the difference. Thanks for sharing your experience.

9

For Ethernet, there is the Energy-Efficient Ethernet (EEE) feature (sometimes called Green Ethernet). It basically disables the power-hungry parts of the ports when it detects no activity.

For any kind of cosumption measurement, it would be senseful to know what setting and state EEE had on your system.

Use ethtool lan1 and ethtool lan1 --show-eee to see what is going on.

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Interesting. Only cases where I measured below 0.5W were links downgraded to 100Mbit.

Sorry for misunderstanding. It was generic measurements, not MOX. Fixed.

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@peci1 Thanks for the EEE/Green Ethernet tip. I knew it exists but did not know it must be supported on both ends or it does nothing. All 0.5-2.0W measurements were against brand new switch that promised EEE but this looks like its EEE/Green Ethernet support is maybe broken.

I factory reset, connected via eth0 and tried again, in order of test:

MOX-C connections Ports bridged lanX speed Total Power
none all 1G 4.1W
lan1-lan2 all 1G 5.5W
lan1-lan2, lan3-lan4 all 1G 6.1W
lan1-lan2, lan3-lan4 only eth0 1G 4.4W
none only eth0 1G 4.3W
none all 1G 4.3W
lan1-lan2, lan3-lan4 all 100M 4.9W
lan1-lan2, lan3-lan4 only eth0 100M 4.3W
ā€” ā€” ā€” ā€”
eth0-lan1 only lanX 1G +1.0W

This confirms both that port with traffic vs idle port is big difference when EEE works right and also difference between port running at full gigabit vs port degraded to 100M (ethtool -s lanX speed 100 duplex full autoneg on)

PS: Command for showing EEE is ethtool --show-eee lan1. Your order shows error.
Command for showing port speed is ethtool lan1, grep for ā€˜Speedā€™.

Edit: Figured why I measured 0.5W/port before. MOX-Aā€™s eth0 shows ā€œEEE status: disabledā€

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Yes, there are many switch chips out there that have EEE support in datasheet, but when you look up Errata of the datasheet, youā€™ll find that EEE is implemented, but wrong, so in order to be able to actually use the chip, you have to disable EEE in its firmware/config. Thatā€™s a pretty sad story, but Iā€™ve seen this with multiple vendorsā€¦

13

Good catch. My MOX-A shows the same. I see:

root@turris:~# ethtool --show-eee eth0
EEE Settings for eth0:
        EEE status: disabled
        Tx LPI: disabled
        Supported EEE link modes:  100baseT/Full 
                                   1000baseT/Full 
        Advertised EEE link modes:  Not reported
        Link partner advertised EEE link modes:  Not reported

Is it because of the peer that it is disabled? Or, it is because of MOX-A?

14

Thank you for confirming. Looks like eth0 EEE is default off. After ethtool --set-eee eth0 eee on I see same power as with lanX.

If you try this expect changing eee resets link so it will be down for like a second.

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