Question: Memory's Impact on Battery Life

[Mamapajama]

Hi all,

I just purchased an Acer TM4402 that came with 512mb ram (sweet lappy by the way). This thing's gettin just a little under 3hrs battery life on the average which is just about what it's rated at... but I was wondering, if I add another gig of ram, will that significantly increase battery life since the hard disk won't have to be written to as often?

(by the way, the more "obvious" forms of increasing battery life like dimming the screen, power settings, etc. have already been taken care of.. I'm just lookin for other tips)

About how much time increase in minutes, if any, can I expect from upgrading to 1.5 gig of ram from 512mb? Thanks guys.

 

[Commodus]

It's impossible to say how much you'll gain. Odds are you'll probably get a bit, but it varies from laptop to laptop. It also depends on what you're doing. If you're just checking your e-mail, you'll probably gain jack squat because your e-mail software won't push past 512 MB and it'll have to write a little bit to disk anyways.

 

[Mamapajama]

I occasionally play games on it, in which case I have the AC plugged into it, so it won't matter in that case...

When running on battery, the machine's usually doing a good share of browsing/Word, etc. Would an upgrade be not worthwhile relative to the diddly-squat improvement in battery?

 

[modedepe]

Originally posted by: Mamapajama
I occasionally play games on it, in which case I have the AC plugged into it, so it won't matter in that case...

When running on battery, the machine's usually doing a good share of browsing/Word, etc. Would an upgrade be not worthwhile relative to the diddly-squat improvement in battery?

Based on that you'll probably gain none, or possibly lose a little since the RAM will be using power also.

 

[SoulAssassin]

Originally posted by: modedepe

Originally posted by: Mamapajama
I occasionally play games on it, in which case I have the AC plugged into it, so it won't matter in that case...

When running on battery, the machine's usually doing a good share of browsing/Word, etc. Would an upgrade be not worthwhile relative to the diddly-squat improvement in battery?

Based on that you'll probably gain none, or possibly lose a little since the RAM will be using power also.

Yes, but I'm going to go out on a limb and say the power that RAM is using equals less power than it takes to move the hard drive head. Though that data does need to be read off disk at some point to get into memory so I would say the only time you would see an efficiency in power is when your not swapping to disk because of the additional memory you added. How often that will be depends on the apps that you run. In the end, I would say any gain is immeasurable.

 

[insename2]

i think most of the power consumed by the hdds are from spinning and since its always spinning, not very much?
i would think that more power is consumed by the so-dimm than saved by less moving arms...

 

[vegetation]

Originally posted by: insename2
i think most of the power consumed by the hdds are from spinning and since its always spinning, not very much?
i would think that more power is consumed by the so-dimm than saved by less moving arms...

Actually the read/write process will consume quite a bit more power, often up to 3 watts for a modern lappy drive. Most modern laptop drives at idle consume less than a watt. That's a 200-300% increase in power consumption. But as mentioned, it depends entirely on what you do with your system whether you gain any noticeable benefit and what you started off with. For example, someone who has only 256mb running winxp upgrading to 1gb will likely see far better results than one who is going from 1gb to 2gb.

 

[Ionizer86]

If some computer has, say 1GB of ram in 2x512 config, but only 400MB are in use, must the system supply power to the entire gig, just 400MB of the ram, or 512MB (to power one stick)?

 

[insename2]

afaik it will supply to the whole thing, but then i mostly do desktops and we dont worry about power management, i suppose it is possible to undervolt but keep in mind that the system's stability is dependent upon both sticks of ram... hence undervolt ram = more likey for mistakes

 

[insename2]

Originally posted by: vegetation

Originally posted by: insename2
i think most of the power consumed by the hdds are from spinning and since its always spinning, not very much?
i would think that more power is consumed by the so-dimm than saved by less moving arms...

Actually the read/write process will consume quite a bit more power, often up to 3 watts for a modern lappy drive. Most modern laptop drives at idle consume less than a watt. That's a 200-300% increase in power consumption. But as mentioned, it depends entirely on what you do with your system whether you gain any noticeable benefit and what you started off with. For example, someone who has only 256mb running winxp upgrading to 1gb will likely see far better results than one who is going from 1gb to 2gb.

how bout that... 5400rpm < moving arms...