Raspberry Pi Power Consumption

Out of nothing more than mild curiosity, I bought an in-line voltmeter/ammeter to see how much of the 2.5amp supply my raspberry pi needed.

I am surprised to see that the official 5volt power supply is giving 5.3 volts and even more surprised that the Ras Pi 2v2 is using under 0.5 amp (even with a USB memory stick plugged in.

Two of the meters both give similar readings.

Are they faulty, or is the Pi really only using less than half an amp? Anybody else done a similar measurement?

For an idle ARM-based SBC, that sounds about right. Most of that ~2.5amp recommendation is to allow you to plug in power-hungry USB devices, and the Pi 2/3 use ARM cores that are focused on energy efficiency rather than performance (e.g. Cortex-A15), so even if you’re stressing the CPU it won’t go up by that much (although the Pi 3’s CPU is a bit more hungry than the 2’s). Not sure how much power the GPU uses when it’s running at full tilt.

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

I measured my Pi (1) with one of those plug-in USB meter gadgets.

5.07V, 0.55A. When running normally, with keyboard, mouse, and a small hub.

The Pi Zero in OSMC measured 0.04A, I suspect the meter might have had difficulties with the unusually low power, as that does seem insanely low…

…then again, it IS an ARM device. ;-)

[edit: actually, the site linked above suggests 0.08A-0.12A for the Zero, so…]

OK. Thank you both for the helpful comments.

The Pi was in an almost idle state. My real time project never really wakes up a Pi, even when ‘busy’ with lots of inputs.

On my Pi GPS unit (model A+, no monitor, OLED display) it uses 180mA at 5.2V. With an HDMI monitor lead plugged in, this rises to about 500mA.

Connected networking and HDMI make a huge difference in my experience. And power-hungry USB devices like harddiscs and optical drives obviously.