I have seen more than 10W from a PoE powered Pi4B-2GB (no local storage, only ethernet cable). If USB is lets say 5.9W, the 15W total might still be reached.Reading more I think this is a “backpower” issue and, interestingly, everything seems to work fine without the USB hub. Do I really need a powered hub for an NVME drive? Any way I could get some kind of data corruption without one?
Could be. If your hub puts anything on the D+/D- pins it will confuse the PMIC and stop the Pi booting.
Regarding the 15W mentioned above, that isn't the applicable limit. That's what the recommended PSU can supply.
The limit for bus powered USB devices is 6W (1.2A @ 5V) and that's shared not per device.
In addition, ondemand is now the default for the kernel AFAIK, not powersave. Although this will be after there firmware has done its thing, so when kernel gets active.
Statistics: Posted by redvli — Thu Dec 05, 2024 2:32 pm