General discussion • Re: Where to find RTC and Linux debug port connectors for Pi 5

That cable is EXTREMELY critical, in simple terms apply ohms law.

ive been testing several usb-c cables i have, and that is immediately obvious as well

ive got a cheap/thin amazon basics C<->C cable, and with a 3A source, the voltage drop is so bad, my pi5 cant even boot from a usb thumbdrive
i also have a much better u-green C<->C cable, same 3A source, but under full cpu load, it still gets some voltage drops
the pi4 PSU, also 3A, is rock solid, i'm not sure if its the extra 0.1v (5.1 supply), and/or better wires (no data like the ugreen, so it can be thicker, while feeling thinner)
here, i rigged "vcgencmd pmic_read_adc" into prometheus/grafana, with the pi4 PSU, and then hit it with an all core stress-ng

VDD_CORE jumped from 0.7W to 4.7W
the 5v rail dipped from 5.18v to 5.07v
and the total wattage (not sure what is unmeasured) went from 1.93W to 6W
but then it began to thermal throttle (i need to get the heatsink), and the figures began to return back towards idle
and this is with the u-green cable, it diped as low as 4.78v, but it also began to thermal throttle

Statistics: Posted by cleverca22 — Sun Dec 10, 2023 5:46 am

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