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

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'
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