[ltp] battery drain while asleep?

[Shem Multinymous]

On Fri, Nov 14, 2008 at 8:19 AM, Henrique de Moraes Holschuh
<hmh@hmh.eng.br> wrote:
> On Fri, 14 Nov 2008, Michael Gaber wrote:
>> it was about 13h so 10Wh/13h~0,75W
>> i think it should be possible to get a T-Series thinkpad down to 300mW
>
> RAM eats up a lot of the power used doing S3 sleep.  The bigger the ammount
> of RAM, the bigger the ammount of power needed for self-refresh.

My reading of DRAM specs is that power consumption for self-refresh is
typically minuscule.
Still, it may be possible to power off unused DRAM modules.
The Intel 915 (and presumably later) chipsets support memory
powerdown, and Linux's memory hotplug should be able to make the
kernel evacuate a range of memory. The BIOS, of course, may choke on
this.

  Shem