[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: [sid] lenovo thinkpad x200s discharge battery while on hibernate

Celejar wrote:
> By 'hibernate', I assume that we're talking about suspend-to-disk.

I am assuming that too.  Hibernate is suspend-to-disk and the machine
is then turned off.  Standby/Suspend would be suspend-to-ram and would
need continuous power to keep the ram alive.

> What do you mean by 'enough to run the power button'?  When suspended to
> disk, isn't the system completely off?

Most of the system is off.  But the power button is electronic.  It
takes just a tiny little bit of power to sense the button and then
activate the power supply.  It is almost a zero power state.  Power
isn't needed for the computer since nothing is running but power is
needed for the switch.

In the old days the power switch was a simple physical power switch.
The switch went "clunk" and power was either connected or
disconnected.  The machine couldn't turn itself off but could only say
it was now safe to remove the power.  But these days almost all
computers use a smart electronically driven power supply that can turn
itself off and on.  Or allows the machine to wake up automatically
upon a set time.

Also machines might be configured for a Wake-On-LAN magic packet in
which case the networking would also be active.  You may have seen
Wake On LAN available in the BIOS settings.  (I don't know if the x200
in particular has WOL.)  The LAN would of course draw significantly
more power, for a laptop.  But for a desktop the amount of power to
drive the LAN card is small.  A lot of larger sites configure machines
for wake on LAN so that they can wake them up in the middle of the
night for backup and for updates and then shut them down again when
that is done.

Hmm...  Thinking about this more makes me think you should probably
make sure that Wake-On-LAN isn't enabled in the BIOS.  Since that
would need to keep the LAN powered up while off or hibernated.


Attachment: signature.asc
Description: Digital signature

Reply to: