Post #1275623
2024-09-01 22:49 UTC
@manawyrm something worth trying is dropping the 5V supply voltage for the Pi down to 4V. the limited schematics available show the board using PAM2306 and RT8088 buck regulators to derive the 3.3V and VDD_CORE voltage rails. the PAM2306 goes from 60% efficient at 5V up to 85% efficient at 4V in, which is a major increase. the RT8088 gains a couple of percent efficiency by dropping to 4V too.
Replies (2)
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@manawyrm@chaos.social 2024-09-01 22:52
@gsuberland Uhhh! Interesting! That should be easy to test, thanks. Not sure what the camera module thinks of this, but I‘ll give it a shot!
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@manawyrm@chaos.social 2024-09-02 07:32
@gsuberland Holy shit. I just tried this and yes, you're totally right. The switching regulator get's _vastly_ more efficient at lower voltages. I saved 20% total energy by reducing the input voltage down to 3.6V (updated blog post): https://kittenlabs.de/blog/2024/09/01/extreme-pi-boot-optimization/#reducing-input-voltage