[sf-lug] will increasing RAM increase power draw during suspend-to-RAM?

Mark K. Zanfardino mzanfardino at gmail.com
Thu Sep 4 10:02:36 PDT 2008


This is a very good question and it brought to mind the fact that my 
laptop does not maintain it's battery life nearly as long as it had 
prior to my adding an addition 1GB SODIMM to the existing 512MB base RAM 
installed.  Prior to the expansion I could safely leave my laptop in 
sleep mode for nearly 24 hours; now it doesn't last 12.  I haven't run 
any conclusive tests to see how long it will last, but clearly there has 
been a dramatic decrease.

NOTE: I wasn't looking at the RAM initial for this decrease as I've made 
a number of changes including installing a larger HD (moved from a 40GB 
4400rpm drive to a 120GB 5400rpm drive) and installing a newer release 
of Kubuntu (I was running 7.04 and am now running 8.04.1).  It seems 
unlikely that the drive would be the issue, as it should be parked while 
sleeping.  The OS might be an issue, I guess, but I can't be sure.  
However it seems the RAM the likely suspect.

I'd be interested in reading any other's thoughts on this issue.


John Magolske wrote:
> When suspended to RAM, a laptop's battery is slowly drained.
> My understanding is that this power is going towards keeping
> the RAM active. I'm wondering how much of the total power draw
> is is being consumed by the RAM chips. Would doubling the
> amount of RAM from say 512MB to 1GB have the effect of roughly
> doubling the power consumption while suspended?
> John

More information about the sf-lug mailing list