Effect on battery life of adding a DDR3 memory module

Hi,

I am looking to get a HP 2540p with 4GB DDR3-1333 and a intel X18-M 160 GB.

I have to choose between 32bit W7 or 64bit W7. If I would go for 64 bit W7 the I could add a 4GB memory module so the system has 8 GB (handy for graphics and video processing), but I found out a DDR3 SO-DIMM consumes about 2 - 3 watt.

During (very) light use when travelling the extra 4GB serve no purpose of course and will only draw power.

so would adding a module shorten battery life by about 10% (assuming the module draws 2,5 watt and the entire system draws with very light use about 25 watt? (i7 640LM, X18-M, LED screen, X4500HD embedded on the i7 processor)

and 5% in case of heavy use (assuming the full power draw is 50 watts).


or do memory modules go to sleep as well if they are not used?

Thanks,

Andries

 

DDR3 memory uses less power tham DDR2. I think the battery life difference will be 1-2 minutes max.

 

Don't worry about it. The memory modules use less power while idle than while being used, and your figure for power consumption is likely for full blast, not at idle.

 

Your power draw figures are too high for the 2540p. My 16" Acer on low usage w/ more power hungry components draws around 13W (measured by RMClock and estimated with actual battery life). Adding another stick of memory will give a negligible increase in power consumption if you're just doing basic tasks on the go.

 

the effect will really be little... it will be at most 5 mins.. but really, it barely uses as much power ...