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have anyone measured power consumption of the newly-introduced "off" state via long-press of the Fn-F10 combination on the Raspberry 400 model?

https://www.raspberrypi.org/blog/designing-raspberry-pi-400/

"We also have a feature that is completely new to Raspberry Pi products: an on/off button! Power off is achieved by holding down Fn+F10 for two seconds. This is a soft control that negotiates with Linux to shut down, so you don’t corrupt your memory card or your USB drive. Power can be restored by pressing F10 (or Fn+F10)"

https://www.raspberrypi.org/blog/raspberry-pi-400-the-70-desktop-pc/

"It uses the Holtek keyboard controller to enter (and exit) an ultra-low-power mode where the main PMIC is completely powered down."

Looking for my pre-order... Thanks.

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  • This used to be the default for the Pi4 until the luddites convinced the Foundation to change the default so their dodgy HATs would work. See raspberrypi.stackexchange.com/a/114108/8697 From memory this was ~30mA. It has been easy to safely shutdown the Pi with a button for years. – Milliways Nov 5 '20 at 11:16
  • Hmm, are you saying that this poweroff is not different from the "fake" one we have on RPi4B? – lzap Nov 5 '20 at 13:21
  • I don't know what you mean by 'the "fake" one'. Statements by the designer "Raspberry Pi 400 has the same circuit layout of the power management, processor, and memory as Raspberry Pi 4". The PMIC is capable of shutting down all power except 5V, so residual current should be the same as Pi4 (which is keyboard plus mouse and monitor). I assume they wouldn't have the same dumb patch for HATs. – Milliways Nov 5 '20 at 23:21
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A similar question has been asked and answered for the RPi 4. I have also posted a more detailed account on GitHub.

You won't find anything there on the 400. I would guess that the hardware and firmware relevant to this question are not too different between the 400 and the 4 - but that will always be a guess because the Raspberry Pi Foundation has chosen not to disclose either the hardware design or the firmware design. I'll avoid temptation to rant here - this is the sad but true situation.

Anyway - I'll guess that when the power consumption is measured in the 400, it won't be substantially different than the 30-40 mA we currently see on RPi 4.

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  • Thank you very much, I am not an expert in RPi or hardware, I am just asking if I can let my kid to keep it powered down via Fn-F10 and not wasting energy. So if I read all of this correctly, I can expect either 2.7 Watt or 0.02 Watt consumption when powered down, depending on what they implemented? – lzap Nov 9 '20 at 8:31
  • Oh you say 30-40 that's 1.9 Watt. Not bad, not good. – lzap Nov 9 '20 at 9:03
  • @lzap: P=V x I = 5V x .03A = 0.15W to 0.2W. And wrt your 1st comment, putting Pi in a "sleep" state could save enough in electrical energy costs in a year to pay for another RPi: At $0.133/kwh for electrical energy, an RPi that runs 24x365 costs about: 24 x 365 x 0.5 x 5/1000 = $22 per year. "Sleep" mode power consumption for the same period is ~ $2 per year. – Seamus Nov 9 '20 at 15:04
  • Thank you, I am not into hardware :-) – lzap Nov 10 '20 at 9:48
  • @lzap: I'm so sorry - that must be incredibly boring for you :-0 lol – Seamus Nov 10 '20 at 16:54

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