Disabling memory to save power

[Stuh505]

I'm interested in upgrading my laptop's memory from 4 GB to 8 GB. However, i dont always need the extra memory, and the increased power consumption would not be insignificant. My processor is i7 2620-M which I assume is bundled with the memory controller. I'm wondering if anyone knows whether or not this chipset is designed to do intelligent power management by essentially shutting down power to memory modules that are not needed, or if there is a way to disable a memory module manually through something similar to the device manager

 

[ninjaturtle]

I don't believe there is.

 

[Cerulean]

You'd have better benefits disabling your mechanical HDD and CPU than you would RAM.

 

[Slava]

You can make processor throttle to a slower speed. But ram-wise, no way to do that.

 

[cyclone3d]

If you are running a mechanical hard drive, you will benefit WAY more from switching to an SSD than worrying about the very small amount of power that larger and/or more RAM sticks would use.

 

[bonehead123]

Ram takes such a miniscule amount of juice, even if there was a way to shut it off, it would NOT be worth the trouble anyways.......

Do the SSD thing & THEN you will see significant energy savings.

And besides, if you could shut down part of it, when you started to do something that needed it, would you REALLLLY be willing to wait for it to power back up.........N O T

 

[Stuh505]

Ram takes such a miniscule amount of juice, even if there was a way to shut it off, it would NOT be worth the trouble anyways.......

Do the SSD thing & THEN you will see significant energy savings.

And besides, if you could shut down part of it, when you started to do something that needed it, would you REALLLLY be willing to wait for it to power back up.........N O T

Thanks for the suggestions -- I'm already aware of the order of precedence where power savings can be made and already have a SSD hard drive.

Your estimate that the ram uses a miniscule amount of power is not true. I have a beefy (in comparison to my other 4 cell laptop that runs for 8 hrs) 6cell battery with 70WH and my current battery life is probably about 5hr indicating an avg system draw of about 14W. I estimate that another dimm would draw approx 2W which would reduce battery life by 40 minutes.

 

[E4g1e]

Thanks for the suggestions -- I'm already aware of the order of precedence where power savings can be made and already have a SSD hard drive.

Your estimate that the ram uses a miniscule amount of power is not true. I have a beefy (in comparison to my other 4 cell laptop that runs for 8 hrs) 6cell battery with 70WH and my current battery life is probably about 5hr indicating an avg system draw of about 14W. I estimate that another dimm would draw approx 2W which would reduce battery life by 40 minutes.

Actually, it doesn't quite work out that way: A given mobile memory controller is designed to operate in dual-channel mode - and that's the basis of the battery life claim. If a memory module is removed such that the controller runs in single-channel-only, the system's total power draw will be the same as the same system in dual-channel mode. Therefore, the CPU's IMC will draw exactly the same amount of power whether the memory is in single-channel or in dual-channel. With one module in single-channel mode the laptop will draw the same number of watts as an otherwise identical laptop with a dual-channel memory setup. In other words, you will not increase the battery life much, if any, with a single-channel memory setup (in fact, you'd add only about 5 minutes of battery life at most). Besides, the SO-DIMMs that laptops use draw less power than the standard-sized (desktop) DIMMs that your power figures are based on.

Now, if the laptop supports two DIMMs per memory controller channel, then the extra DIMMs will start eating up the run time of a laptop.