Maximize battery life by choosing the right hardware?

I'm trying to configure a laptop to maximize battery life, and some of the parts, I have no clue what helps:

CPU: T5xxx series vs T7xxx series -- was there improvement in battery life? Or T5xxx has better battery life because low speed = low consumption?
OS: Does Vista manage battery life better than XP?
RAM: More RAM = more battery life because less access needed to moving-part HD, correct?
HD: 5400rpm or 7200rpm? 60Gb or 200Gb? (I know SSD's are the most battery-saving, but at 500 bucks a pop? No thanks)
AC Adapter: 65W or 90W? Or doesn't matter at all?

Thanks.

 

I believe at a given speed the 7xxx series will draw less power than the 5xxx series. I also believe XP in general uses less battery, but then Vista might MANAGE the battery life better. Not so sure about that RAM part, but it seems logical? A 5400 RPM hdd will draw less power than a 7200RPM hdd. The AC adaptor won't affect battery life.

 

I get about the same battery life using Vista or XP. The biggest factors in battery life are screen size/brightness and the battery itself. The faster you charge the battery, it usually wears it out faster.

 

integrated graphics are going to use a good amount less power than dedicated options.

 

You can't split the way you want as many factors come into play. For example the Intel people were talking about the efficiency improvement of 28% w/Santa Rosa over the previous Napa platform. Also MFG's have done many things with HDD's to lessen the power usage between @5400 and @7200. As I have seen stated correctly several times on NBR if it takes longer to do the same task are you really saving power? The way you are looking at it while can be done. My advice is get a notebook w/Santa Rosa, use the Intel X3100 IGP not dedicated graphics and check out the particular HDD for power usage. If battery life is the most important. Other than buying a notebook specially designed for that purpose w/ULV CPU That is what I would do. And yes the Adapter has little to do w/battery life, expect if it requires a higher capacity one you can bet the notebook likely draws more power.

 

I have a theory that the CPUs with 4MB cache (T7200 and upwards) leak more power than the CPUs with 2MB cache.

Santa Rosa should give better power savings because it introduces an 800MHz lower voltage CPU mode with half speed FSB. However, the improvement seems to be quite small.

You can compare HDD power consumption at the Tom's Hardware 2.5" HDD charts. Turbo Memory may also help -see Anandtech's analysis. ReadyBoost can also help under some conditions.

Some manufacturers seem to be better than others in building in good power management but you will only find out who they are by reading reviews and seeing the results of the battery life tests.

Vista can give better battery life than XP, if you disable all the eye candy, because it has improved access to power management options.

The LED backlit displays also improve battery life because they are more efficient.

John

 

I'm trying to squeeze the most battery life out of this laptop but with a dedicated graphics card, that's why I didn't ask about GPUs.

Does harddrive capacity matter at all?

 

Here is a link to check out power consumption and much more Link.

 

So WXGA will draw less power than a WXGA+ screen? Or it won't matter because both are 14" (in my case)? (Both are TFT I believe, not LED)

 

I believe that the few pixels means slightly lower power consumption, but the main power used by the LCD is for the backlight.

If you want to get more battery time with a 1280 x 800 display get a smaller (13.3" or 12.1") notebook so there is a smaller panel to illuminate. Sensibly, the backlighting power will be proportional to the display area.

John