Power saving on your plugs: Pogoplugs V2/V3/V4, Dockstar, GoFlex Home/Net and other Kirkwood NAS boxes

I am starting this thread to hear users experience on the power saving topic on these small plugs. Aslo your bigger NAS such as the NAS 310/320/325/326...

For example, the Dockstar has a power adapter that outputs 12V DC, 1.5A (?). In a typical usage scenario, you would plug in a USB 2.0/3.0 rootfs.

- What are actual operating Voltage and Amps that you know the Dockstar is drawing?
- Have you used cpufrequtils to slow your CPU to a lower CPU frequency? i.e.using "ondemand" or "powersave" setting. And what is the power drawing during that time?

cpufreq-info

cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
  driver: kirkwood-cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 5.0 us.
  hardware limits: 400 MHz - 1.20 GHz
  available frequency steps: 1.20 GHz, 400 MHz
  available cpufreq governors: powersave, userspace, conservative, ondemand, performance
  current policy: frequency should be within 400 MHz and 1.20 GHz.
                  The governor "ondemand" may decide which speed to use
                  within this range.
  current CPU frequency is 400 MHz (asserted by call to hardware).

-bodhi
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Edited 1 time(s). Last edit at 10/23/2018 09:42PM by bodhi.

Could do the test after re-fill an USB Stick with a running linux for my dockstar.

For emergency purpose I am now using an old PC with fujitsu siemens industrial atx board and Core2Quad CPU.
This one consumes ~ 55 Watt without Monitor (measured with https://avm.de/produkte/fritzdect/fritzdect-200/), but including the 3,5" USB HDD moved from the dockstar prevously used as home server.

This means in german prices for electricity ca 0.40 € per day or 11 € per Month ...

Will return results after Dockstar is up & running again ...

First test with "conservative" setting
- No usb hard disc connected
- Quite "clean" Linux-1.18-4 installed according to your HowTo here in the forum.

Started Operating system.
SSH Console opened

Following conditions

root@debian:~# yes > /dev/null &
[1] 1600
root@debian:~# yes > /dev/null &
[2] 1601
root@debian:~# yes > /dev/null &
[3] 1602
root@debian:~# yes > /dev/null &
[4] 1603
root@debian:~# cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
  driver: kirkwood-cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 5.0 us.
  hardware limits: 400 MHz - 1.20 GHz
  available frequency steps: 1.20 GHz, 400 MHz
  available cpufreq governors: powersave, userspace, ondemand, conservative, performance
  current policy: frequency should be within 400 MHz and 1.20 GHz.
                  The governor "conservative" may decide which speed to use
                  within this range.
  current CPU frequency is 1.20 GHz (asserted by call to hardware).

Results in 390 mA current draw at the 12 Volt line (exact Voltage not measured)

Killed the four CPU-load producing processes ....

root@debian:~# kill -SIGSTOP 1600
root@debian:~# kill -SIGSTOP 1601

[1]+  Stopped                 yes > /dev/null
root@debian:~# kill -SIGSTOP 1602

[2]+  Stopped                 yes > /dev/null
root@debian:~# kill -SIGSTOP 1603

[3]+  Stopped                 yes > /dev/null
root@debian:~# kill 1600

[4]+  Stopped                 yes > /dev/null
root@debian:~# cpufreq-info
cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009
Report errors and bugs to cpufreq@vger.kernel.org, please.
analyzing CPU 0:
  driver: kirkwood-cpufreq
  CPUs which run at the same hardware frequency: 0
  CPUs which need to have their frequency coordinated by software: 0
  maximum transition latency: 5.0 us.
  hardware limits: 400 MHz - 1.20 GHz
  available frequency steps: 1.20 GHz, 400 MHz
  available cpufreq governors: powersave, userspace, ondemand, conservative, performance
  current policy: frequency should be within 400 MHz and 1.20 GHz.
                  The governor "conservative" may decide which speed to use
                  within this range.
  current CPU frequency is 400 MHz (asserted by call to hardware).

Remaining 320 mA

Unfortunately I only have a quite old Metek OEM (Voltcraft) Multimeter. That provides only 20A 200 mA and 2 mA ranges, so that I have to use 20 A range ... that means resolution is only 10 mA.



Edited 3 time(s). Last edit at 10/23/2018 04:28PM by Martin aus Dortmund.

Martin,

Very cool! 390 and 320 mA are excellent.

I had suspected that Amp could go down more at 400MHz. And Voltage is at constant ~12V. This test has shown that the cpufreq governor is quite useful in power saving. Especially if we have USB HDD plugged in (be able to bring it down at idle and HDD sleeping).

Good info! I hope to see more test cases. And also from others who have larger NAS such as the Zyxel NSA310/320/325.

I'll add this topic to the Wiki.

-bodhi
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Forum Wiki
bodhi's corner (buy bodhi a beer)

The Pogoplug's DC 12v power consumption doesn't take into account the efficiency of the AC wall wart supplying 12v power to the box. I'm thinking that an AC amp meter with the wall wart plugged into it would show somewhat less actual efficiency between 1.2ghz and 400mhz. The wall wart could be analyzed by putting a load on the dc output of 390 and 320 ma and measuring the AC draw at both output currents.

In my case, I have a GoFlexNet with two 500gb 2.5" hard drives that never go into power-save or power-down mode. Since I use it mostly for sharing music and some video for a few hours a day, I would think that allowing the SATA drives to be brought down when idle would greatly reduce the power consumption at the AC wall wart. I'll look thru the other threads here and see if someone has tested and implemented such a hack.

atglabs,

It is in the Wiki post:

https://forum.doozan.com/read.php?2,23630

Quote

Tools

Debian hdparm (HDD spin down)
Hard Drive Idle Tool (an alternative to the standard Debian hdparm)
Apt-cache server

-bodhi
===========================
Forum Wiki
bodhi's corner (buy bodhi a beer)

Some new Power Measurements.

Since Dockstar and USB HDD are powered both by separate wall power supplies, I have used a multi connector strip and used my "AVM Fritz!DECT 200" https://avm.de/produkte/fritzdect/fritzdect-200/ for measuring.

Leistung aktuell 5,86W min. 5,79W max. 5,93W

Power consumption reduced to 10 % of the one measured for my Linux PC ....

EDIT:
According to https://forum.doozan.com/read.php?2,72159 I have started Radicale CalDav server on my dockstar.
That increases the power consumption to 8.5 Watt - after some minutes, the power consumption sunk to 5,8 Watt again....

EDIT2:
I Am actually separating data types to different partitions of the attached USB HDD. Multimedia/Entertainment Data (Videos, Audio etc) is moved from "data" partition to another partition.
So the USB is permanently working actually.
10 Watt under this conditions ...

166 Wh per day...



Edited 2 time(s). Last edit at 11/06/2018 02:58PM by Martin aus Dortmund.