<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body dir="auto"><div dir="auto">Supply current rises linearly with clock rate. </div><div dir="auto">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.</div><div dir="auto"><br></div><div dir="auto"><br></div><div dir="auto"><br></div><div dir="auto"><br></div><div id="composer_signature" dir="auto"><div style="font-size:12px;color:#575757" dir="auto">Sent from my Verizon, Samsung Galaxy smartphone</div></div><div dir="auto"><br></div><div><br></div><div align="left" dir="auto" style="font-size:100%;color:#000000"><div>-------- Original message --------</div><div>From: Trampas Stern via TriEmbed <triembed@triembed.org> </div><div>Date: 8/17/23 9:11 AM (GMT-09:00) </div><div>To: Peter Soper <pete@soper.us> </div><div>Cc: Triangle Embedded Interest Group <TriEmbed@triembed.org> </div><div>Subject: Re: [TriEmbed] Raspberry Pi idle current vs clock rate(s) </div><div><br></div></div><div dir="ltr">There are other chips consuming power beyond the processor: <div><a href="https://forums.raspberrypi.com/viewtopic.php?t=152692">https://forums.raspberrypi.com/viewtopic.php?t=152692</a><br></div><div><br></div><div>LAN</div><div>WIFI</div><div>HDMI</div><div>etc </div><div><br></div><div>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. </div><div><br></div><div>This most likely does not solve your problem but might answer your question. </div><div><br></div><div>Trampas</div></div><br><div class="gmail_quote"><div class="gmail_attr" dir="ltr">On Thu, Aug 17, 2023 at 1:03 PM Trampas Stern <<a href="mailto:trampas@gmail.com">trampas@gmail.com</a>> wrote:<br></div><blockquote style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex" class="gmail_quote"><div dir="ltr"><a href="https://www.pidramble.com/wiki/benchmarks/power-consumption">https://www.pidramble.com/wiki/benchmarks/power-consumption</a><br><div><br></div><div><br></div></div><br><div class="gmail_quote"><div class="gmail_attr" dir="ltr">On Thu, Aug 17, 2023 at 12:54 PM Peter Soper via TriEmbed <<a href="mailto:triembed@triembed.org">triembed@triembed.org</a>> wrote:<br></div><blockquote style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex" class="gmail_quote">
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<div style="font-family:monospace"> <span style="margin-top:0px;margin-bottom:0px" dir="ltr">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?</span>
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<br> <span style="margin-top:0px;margin-bottom:0px" dir="ltr">Pete</span>
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