On 2021-04-12 9:28 a.m., D. Hugh Redelmeier via talk wrote:
I always thought that shutting down a Pi really left it on. That's one reason some people like Pi power supplies with a switch. To what extent is that true?
It does: it just leaves the processor halted. So the other peripheral chips are still drawing power.
How much power is saved? I delayed sending this message, hoping to add information about this but I'm just not getting to the experiments.
Not much, but then, a Raspberry Pi doesn't draw much even running flat out. There are fancy Raspberry Pi add-ons that provide a proper logic-controlled shutdown and poweroff, but they typically cost about the same as a Raspberry Pi, or about two year's energy cost for running a Raspberry Pi 4B flat out. cheers, Stewart