RAM; Power/Heat Difference, 2x1gb to 1x2gb ??

[dozer]

T60 or T60p: Has anyone swapped the stock 2pcs of 1gb for a single 2gb stick, AND measured power-consumption and temps both before and after?

I'm embarked on a project to see just how low a T60p can go, in terms of power....from simple plug-in changes, to Vmodding the ADP3207 and MAX1993.

RAM's a dead-easy thing to change, so worth investigating.

What, if anything, does this change buy, in terms of watts saved and degrees lowered?

thanks!

Richard

[visionviper]

It certainly lowers the wattage used by ~2w. Heat? Maybe a little. Most modules simply get warm instead of hot.

[dozer]

thanks for the word VV.

That 2w difference you actually measured before/after, right at the time of the swap, with identical conditions? Just want to verify that it's hard data, not just a guess.

ps; 2 watts is a lot of reduction! That's a full 10% of the 'browsing' draw of my t60p. I'll take it!

Especially given how cheap and easy this particular 2 watts comes.

If anyone else has done this swap, and measured power while doing so, please add your info here.

PS; and if anyone has a T60 2gb stick gathering dust, please PM me.

thanks,
Richard

EDIT: I just noticed today in the HMM that a single 2gb >533mhz< pc4200 module was listed as a T60 configuration! I didn't think a t60 would run with 533 ram....huh... I suppose the chipset must detect the ram-type and automatically step down the ram-bus speed.

[visionviper]

That 2w difference you actually measured before/after, right at the time of the swap, with identical conditions? Just want to verify that it's hard data, not just a guess.

It's not entirely a guess, but there is estimation involved. I did a quick lookup of what the watt usage of various modules and it seemed that many of the newer DDR2 modules use about 2w. So my guess is that by going from 2 modules to 1 that you will save anywhere between 1 and 2w because you will be going to a higher density, single module.

[dozer]

It's not entirely a guess, but there is estimation involved. I did a quick lookup of what the watt usage of various modules and it seemed that many of the newer DDR2 modules use about 2w. So my guess is that by going from 2 modules to 1 that you will save anywhere between 1 and 2w because you will be going to a higher density, single module.

ahh...ok, I appreciate you clarifying that.

I hope someone else will chime in who took a look at realtime power-draw in Power Manager, before and after.....because I'm not sure one can simply add up datasheet numbers. That data -might- hold up in real use....but I'm concerned that the way the chipset uses memory might make it not so simple...

thanks again for contributing your thought though.....I hadn't looked up that datasheet info.

Richard

[tomh009]

It's not entirely a guess, but there is estimation involved. I did a quick lookup of what the watt usage of various modules and it seemed that many of the newer DDR2 modules use about 2w. So my guess is that by going from 2 modules to 1 that you will save anywhere between 1 and 2w because you will be going to a higher density, single module.

That does assume, though, that your are going from two old 1GB modules to one newer 2GB module. If the memory technology is the same in all the modules, I would not expect to see an appreciable difference: it's the memory chips that use the power, and bigger chips use more power.

FWIW, my X200s uses about 10W with display brightness low and wireless on. It has two 2GB modules, so based on spec sheets that's a power draw of 4W or about 40% of the total. However, the memory module specs are for operating power, the power utilization when memory is being accessed. In most low-intensity computing, any given memory chip is much more likely to be idle than operating at a given moment in time. And the difference in idle power will be far smaller (at least in absolute terms) than the difference in operating power.

Personally, I would not expect a big drop. But if you can borrow a 2 GB stick from a friend, it would certainly be worth a try.

[visionviper]

That does assume, though, that your are going from two old 1GB modules to one newer 2GB module. If the memory technology is the same in all the modules, I would not expect to see an appreciable difference: it's the memory chips that use the power, and bigger chips use more power.

Not really. If you counted each piece individually maybe, but as a whole a single module will always use less power than multiple modules (that use the same chips). It's not really a question of if there will be a difference, but how much.