• Pi 4 power consumption, my measurements are much less than usually quoted

    From Chris Green@cl@isbd.net to comp.sys.raspberry-pi on Sat Jan 25 11:19:34 2025
    From Newsgroup: comp.sys.raspberry-pi

    I have a 2Gb Pi 4B which I run headless and it has a collection of
    little Python scripts and such which gather data. It also runs
    syncthing so the data gets copied to my desktop machine (and others).

    When idle (or doing not much) it consumes just 316mA which, according
    to my sums is just over 1.5 watts. That's a whole lot less than the
    seemingly always quote value of 2.7 watts.

    This does have some significance for me as I'm considering upgrading
    the Pi B+ that runs all the time on my little boat in France using
    the batteries on the boat. The batteries are kept charged by solar
    panels, during the winter there's not much power to spare.

    One of the many sites that shows 2.7 watts for an idle 4B is this one:-

    https://www.pidramble.com/wiki/benchmarks/power-consumption

    But the figure seems to be that same just about everywhere. I suspect
    this may be the 'idle' figure when running a GUI, mouse, keyboard,
    etc.
    --
    Chris Green
    ยท
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  • From The Natural Philosopher@tnp@invalid.invalid to comp.sys.raspberry-pi on Sat Jan 25 12:16:59 2025
    From Newsgroup: comp.sys.raspberry-pi

    On 25/01/2025 11:19, Chris Green wrote:
    I have a 2Gb Pi 4B which I run headless and it has a collection of
    little Python scripts and such which gather data. It also runs
    syncthing so the data gets copied to my desktop machine (and others).

    When idle (or doing not much) it consumes just 316mA which, according
    to my sums is just over 1.5 watts. That's a whole lot less than the seemingly always quote value of 2.7 watts.

    This does have some significance for me as I'm considering upgrading
    the Pi B+ that runs all the time on my little boat in France using
    the batteries on the boat. The batteries are kept charged by solar
    panels, during the winter there's not much power to spare.

    One of the many sites that shows 2.7 watts for an idle 4B is this one:-

    https://www.pidramble.com/wiki/benchmarks/power-consumption

    But the figure seems to be that same just about everywhere. I suspect
    this may be the 'idle' figure when running a GUI, mouse, keyboard,
    etc.

    Indeed you are most likely right., The power consumption of such a
    machine is utterly dependent on what exactly it is doing. Throw some USB
    disk drives on and you may see up to 25W...

    I am not speaking from facts, but only from general experience, that
    video processing takes power and no GUI will be a huge drop in power. I
    doubt that a keyboard or mouse takes much. But WiFi certainly does and
    so does, to a lesser extent, Ethernet.

    Also it is surprising how many 'authoritative sources' merely cut and
    paste each others data. Without checking.

    E.g once many years ago I was interested in the power to weight ratio of
    WWII fighter aircraft. One German fighter had its power quoted in kW and
    bhp. But they did not match. Clearly someone had transposed two digits . Because they then *did* match.

    I attempted to rectify this, but the original text was reinstated. As
    the figures had been copied from yet another 'authoritative source' and
    in academia, 'authoritative sources' are more true than the real world.

    As with most things in the real world, if you want real facts, measure
    the thing yourself. Don't necessarily rely on 'experts' and 'authorities'
    --
    Gun Control: The law that ensures that only criminals have guns.

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  • From Michael Schwingen@news-1513678000@discworld.dascon.de to comp.sys.raspberry-pi on Tue Jan 28 18:49:48 2025
    From Newsgroup: comp.sys.raspberry-pi

    On 2025-01-25, Chris Green <cl@isbd.net> wrote:
    https://www.pidramble.com/wiki/benchmarks/power-consumption

    But the figure seems to be that same just about everywhere. I suspect
    this may be the 'idle' figure when running a GUI, mouse, keyboard,
    etc.

    I have a RP4(4GB) sitting here in a Rocktech ISG-502 housing, which includes
    a 12V DC to 5V converter. Powering it from 12V, my power supply shows 2.55W after booting (default install, no display/usb devices, one 1000baseT link).

    Without the ethernet link, power consumption goes down to 2.15W.

    That includes the losses from the DC/DC converter and some other circuitry
    on the add-on board (RTC, RS232/RS485 interface).

    cu
    Michael
    --
    Some people have no respect of age unless it is bottled.
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