Beginners • Re: [Pi 4/5] Ways to reduce the Pi's power consumption / heat output?

Read the documents for temp

Very helpful ...

(Hint it is something like vcgencmd measure_temp)

Thank you, that was helpful, because "vcgencmd" one can actually google.

For the Pi4B's I do not use a [PoE HAT but] a TP-Link PoE splitter [...] The PoE+ HAT I don't like, it has a fan and it concentrates the heat generation at the same spot as the PI4 SoC and chips.

Could I use a PoE splitter? Sure. But most are large and of dubious provenance—might as well fit a USB-C power brick somewhere. The point of PoE in this case is to reduce clutter where the (Pi and the) scanner sits. That, and dying power bricks are the most common failure mode for equipment 'round here. The switch has a decent PSU (and a UPS).

Funnily enough the Pi 4 isn't a problem anyway. I just put it together and set it up—the fan hasn't spun up once. (It doesn't need to be explicitly enabled, does it?) The switch says it draws just under 3 W, with occasional spikes to 3.1 W. I might not even need to do anything extra to it (besides disabling WiFi, BT, HDMI, and audio). It's the Pi 5 that's the problem. And that doesn't even have its PoE HAT yet.

underclock it, or maybe do tricks with using less than 4 cores

Thanks, will look into it.

usbip

Hey, that's brilliant. I can think of a million uses for that.

If your Pi 5 fan is always on and always noisy, you have something configured wrong or the fan has a mechanical problem.

It's not always on, it just spins up at the slightest provocation, and often without one. It sounds like all tiny fans do. Configuration-wise, it's possible, but I haven't really changed any defaults yet.

The plan is to optimise performance/W, then play with the fan control until it only comes on under sustained load.

Statistics: Posted by fallenguru — Sat Aug 17, 2024 9:01 pm

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