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The documentation online allows the user to change RAM allocation and CPU clock speed via the config text. However, I am interested in reducing the raspberry pi 3 power consumption while not crippling the board (so full gpio and networking and all stock functionality should be present).

Is there any method to specifically shut down cpu cores, turning the pi into a single core 100mhz machine? I know this will have very little effect on power consumption because the cpu is not the main culprit, but I am trying to simulate a low power device without actually purchasing a low power device.

I know there is functionaliry to over clock and underclock, but I have not been able to find a way to physically power off cores while the pi is running.

Equally, I know there is a way to shut down ethernet and USB ports to save power via a kernel module trick, but equally I have not been able to find a way to manually Power off just ethernet and 3 usb ports. From my understanding that is being controlled by one chip so it is impossible?

The similar question stands for the gpu. Is it possible to shut down the broadcom videocore 4 save power and to only have a 1 core online?

I am aware the broadcom gpu has open documentation so it should be possible to figure out if such functionality is available, alas I am not that technical and I got pretty lost in the document.

Would be grateful if someone with experience weights in here whether any of these things can be achieved through a clever workout or an entire driver rewrite.

Edit: ideally I would like to reduce the idle pi current requirement to below 100ma, so less than 0.5w of power, of course with nothing plugged in, only with wifi enabled.

Ideally below 80ma, but I think I am asking too much

tlhIngan
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Thomas E
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  • less than a 100 ma with wifi enabled seems unlikely. You may want to describe your specific use case as it sounds like a microntroller may be a better choice for your needs. – Steve Robillard Jun 15 '16 at 05:29

2 Answers2

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The Raspberry Pi hardware does not support power management, see this related question. Your best bet is to downclock the CPU. To shutoff USB and/or Ethernet, see this related question.

Community
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tlhIngan
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at least for the pi zero v2, there is an updated answer: you can turn of some cpu cores as decribed here: https://www.jeffgeerling.com/blog/2021/disabling-cores-reduce-pi-zero-2-ws-power-consumption-half

I edited the /boot/cmdline.txt file and added maxcpus=1 after console=tty1, then saved the file and rebooted.

This seems to bring down the powerconsumption to aprox 260mA

rdmueller
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  • Although it is not made perfectly clear in the question, there are some hints there that the OP wants to do this *without shutting down/rebooting*, idea being that it could be put into a sort of low power mode while idle. – goldilocks Dec 13 '21 at 15:44
  • @goldilocks I disagree there because of the mention of simulating a low power device without buying one. – Abel Dec 14 '21 at 03:37