[TriEmbed] Raspberry Pi idle current vs clock rate(s)

[Trampas Stern]

Correct I made mistake and it is linear not exponential.

On Fri, Aug 18, 2023, 9:45 PM jwet <jwet at mindspring.com> wrote:

> Supply current rises linearly with clock rate.
> I =CVF, c is the "dissipation" capacitance = total C of swinging nodes, v
> is swing and F is clock rate.  There is a small constant leakage that
> creates an intercept.  The only power is just charging discharging the bus.
>
>
>
>
> Sent from my Verizon, Samsung Galaxy smartphone
>
>
> -------- Original message --------
> From: Trampas Stern via TriEmbed <triembed at triembed.org>
> Date: 8/17/23 9:11 AM (GMT-09:00)
> To: Peter Soper <pete at soper.us>
> Cc: Triangle Embedded Interest Group <TriEmbed at triembed.org>
> Subject: Re: [TriEmbed] Raspberry Pi idle current vs clock rate(s)
>
> There are other chips consuming power beyond the processor:
> https://forums.raspberrypi.com/viewtopic.php?t=152692
>
> LAN
> WIFI
> HDMI
> etc
>
> Typically power increases exponentially with clock rate.  However I bet
> the OS internally is sleeping the processor when idle, effectively dropping
> clock rate. I doubt your power will drop significantly by underclocking at
> idle unless you disable other chips and peripherals.
>
> This most likely does not solve your problem but might answer
> your question.
>
> Trampas
>
> On Thu, Aug 17, 2023 at 1:03 PM Trampas Stern <trampas at gmail.com> wrote:
>
>> https://www.pidramble.com/wiki/benchmarks/power-consumption
>>
>>
>>
>> On Thu, Aug 17, 2023 at 12:54 PM Peter Soper via TriEmbed <
>> triembed at triembed.org> wrote:
>>
>>> Can anybody speak to this? I'm told (by an eager word-guesser aka "ai")
>>> that a Pi 4 idles around 575mA. If I drop the clock from 1200 to 600mHz (as
>>> low as it will go if my other info is right) I wonder if this will cut the
>>> idle current in half or is it likely to be a larger fraction?
>>>
>>> Pete
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