anarcat
October 16, 2022, 12:43pm
23
So this is something I found when doing initial research on this. In another long thread (12th gen battery questions on linux ), I found:
Yes it sadly is.
I have a magentic USB C cable, when connected direct to a PD|PPS output the LED on in only comes on when a load is conneted, If I connect the other UBC C via a USB A adapter then the LED comes on whether or not there is a load.
It seems the USB A must have power going to it all the time, that the old USB 2 and 3 protocols, the USB C only provides power when there is a connection. Old versus new.
Still I can get over the 1W usage, it’s obscene.
and:
Not all power leakage is through power consumption by the card. The USB-A is dumb, but it also causes a noticeable increase in power usage by the laptop (even in idle). Apparently this is due to some connection that a USB-C-to-USB-A adaptor makes between certain pins of the USB-C that triggers the USB-C interface to do some discovery about possible PD requirements, and this then uses a noticeable amount of power. Since laptops with native USB-A ports don’t tend to have this problem with those, …
My bet is that 12th gen somewhat fixed that problem (down to ~10mW) for runtime, but not suspend, as the numbers i’m getting on suspend are in the same order of magnitude of those reported above (i’m getting 300-500mW, they’re reporting ~1W).
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