On a test I wrote the Zero 2 consumes 730 mA in 64-bit mode but only 580 mA in 32-bit mode.Your remark about a more powerful usb hub puzzled me somewhat.I think the same idea would work for a Zero 2 cluster provided a USB hub that delivers more power were used.
I did some research into the actual power a rpi zero-2W draws before deciding for this setup, and
based on that I assumed the standard USB 3.0 max of 5 V and 900 mA for each port would be enough for my use case. This hub brings 36 Watts, and I expected it could provide this 900 mA simultaneously to all 7 ports. Specs on the UGREEN cable state a 3000 mA max input limit, so no problem there.
Till now I haven't encountered a problem with 4 zero's attached (1x zero-1 and 3x zero-2W), but I couldn't resist buying a couple of usb power check gizmo's and using those I checked the output to 2 zero-2W's:
- 1. when both in (my) normal use
2. when running a sysbench test on 4 cores on both zero-2W's simultaneously while checking the cpu temperatures
3. when doing a sd-card speed test provided by rpi on both simultaneously.Results are higher than reported here: https://www.jeffgeerling.com/blog/2021/ ... ption-half
- ad1. In normal use the voltage stays slightly over 5V (between 5.005 and 5.025) with mA in between 290 and 330.
ad2. The sysbench test took cpu's to 65,5'C and 69,3'C respectively, drew a top of 575 mA and also caused voltage to drop slightly to in between 4.850 and 4.950.
ad3. The sd-card test had no effect on voltage and the highest current drawn was 380mA.
I suspect this is caused by my 64-bit Pi OS, where the report mentioned a 32-bit version, and the fact that this isn't a fresh OS but a system that has some extra services up and running. I haven't done any change in firmware settings like disabling audio, wifi or hdmi.
viewtopic.php?p=1930593#p1930593
What was the current draw you observed?
Statistics: Posted by ejolson — Mon Dec 23, 2024 12:28 am