USB Power while Computer is Asleep

KitchiRUs · #1 13th December 2012, 09:47 AM

Hi,

First off, I'm running a F17 KDE X64 on my laptop, and I tend to keep it as up to date as I can manage.

There's something I noticed the other day... I have a usb (LED) lamp that I use to illuminate my keyboard when I work in the dark. I'd left my laptop idling for long enough that it went to sleep, but the USB light was still on.

Is this normal behaviour? I didn't think that was supposed to happen. I know Linux usually gets flak about battery management issues, surely something like this would have been noticed by now?

Is there any way to make sure that there's no power going to the USB drives while my computer is switched off?

EDIT: I meant sleeping in that last sentence, not switched off.

nerak99 · #2 13th December 2012, 11:11 AM

On my MAC, it will charge my phone whilst the mac is asleep but not powered off. Therefore it ios normal behaviour for at least two systems.

KitchiRUs · #3 13th December 2012, 11:47 AM

Oh, okay... I was wondering how much of a power drain it was on the system running 3 USB drives while asleep.
I've noticed there's still a bit of power drain while the machine is asleep... so I was wondering how to minimize that.

mkudro · #4 13th December 2012, 11:54 AM

Quote:

Originally Posted by KitchiRUs

Hii,
......it went to sleep,
.....
.....

.... while my computer is switched off?

Sleep or switched/powered off? While your laptop is "sleeping/idling" or in other words suspended to RAM - it is still "powered on", it means that your buttery still powering stuff although on relatively low power, just enough to keep RAM alive. For the rest unless you have it in BIOS specifically setup to power usb it shouldn't have enough power to charge phone for example, or even led lamp. So check you bios settings if anything is mentioned about usb.
But if you powered your laptop off and USB port is still under battery power then you really should take it back for repairs.

KitchiRUs · #5 13th December 2012, 01:29 PM

Sorry, I meant sleeping, not switched off.

I understand that when the computer is suspended that the battery is still running. But I've noticed that Windows 7 (while it was still on my laptop) had really good power management while the computer was asleep and Fedora doesn't do it as well, and I was just wondering why.