"Robin" wrote in message
...
On 22/02/2021 09:50, Adrian Caspersz wrote:
On 22/02/2021 09:14, Brian Gaff (Sofa) wrote:
The whole point though is for that to also be a charger, though I have
to
say I'm not greatly impressed with their efficiency.


To support the ATX soft start button and wake-on-LAN features, PCs have
long offered a permanent 5V standby supply.

So this USB powering thing is using something that was already there as
an independent subsystem. This would be as efficient as a typical plug-in
wall adapter (I'd hope).


I don't think stand-by power consumption is part of the ATX or 80 plus
standards

Yes it is with the ATX particularly.

but the 4 year old PSU driving this post claims less than 0.25 watts.