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kpholmes
December 16th, 2009, 08:56 AM
if i upgrade my laptops ram from 2gigs to 4gigs, but if the amount of sticks i put in the mobo doesnt change, would my laptop be using more power?

Zoot7
December 16th, 2009, 09:01 AM
No, power consumption is governed by the more power hungry components such as the CPU, or GPU and the Hard Drive. Memory has pretty much no effect on the overall power consumption.

hobo14
December 16th, 2009, 09:58 AM
No. It will probably reduce power consumption, because it will reduce disk access.

Grenage
December 16th, 2009, 10:01 AM
Yup. Depending on how much it is used, it will either make no difference or reduce the power used.

LinuxFanBoi
December 16th, 2009, 10:20 AM
Any time you can reduce the amount of time the computer has to spin the hard drive up, you're cutting power consumption.

The biggest power consumers in your PC are hard drives (non SSD), CPU and GPU, excessive CD/DVD access. Also, It's best to limit gaming and high CPU demanding apps when on battery like folding you can tell your using a ton of power when you laptop is running hot. Heat=energy waisted.

handy
December 16th, 2009, 11:32 AM
RAM has to use energy, what else is going to make it work?

http://www.computerforum.com/134016-memory-power-consumption-question.html

Just search the web a bit to find out about it, finding the above link took all of 2 minutes. :)

If you search a little longer, you should find more appropriate energy consumption values, as in they relate to today's technology.

Grenage
December 16th, 2009, 11:41 AM
I had no idea that RAM used anywhere near that much power!

KeLa
December 16th, 2009, 11:45 AM
Basic rule is that faster ram uses more power than slower.
There have been years ram modules for serius gamers that have build in heatsink
in them.

LinuxFanBoi
December 16th, 2009, 11:56 AM
RAM has to use energy, what else is going to make it work?

I think we can all agree that this is the case. but what the OP is asking is if he swaps two modules for another two modules of a higher capacity, is he going to see a significant rise in energy consumption.

I would hazard a guess that while there would be a "rise," it would be negligible and not significant enough to have a noticeable impact on battery life.

insane_alien
December 16th, 2009, 12:07 PM
you'd probably have a greater reduction in battery life from the battery degrading with time over some extra RAM modules.

perhaps if you were plugging in 15 RAM modules there would be a reduction in battery life that is noticeable(assuming everything else including disk access time is the same)

cascade9
December 16th, 2009, 12:19 PM
RAM has to use energy, what else is going to make it work?

http://www.computerforum.com/134016-memory-power-consumption-question.html

Just search the web a bit to find out about it, finding the above link took all of 2 minutes. :)

True, the RAM does need power. That link is amusing (128MB = 8 watts? OK. But that doesn't make 512MB = 32watts).

I reality, as far as I know, changing over sticks to bigger RAM sticks will use a bit more power, but its in the order of 10-20% or so, nothing major. Increases in power consumption from RAM would be offset by lower drive accessing (to a point anyway).


Basic rule is that faster ram uses more power than slower.
There have been years ram modules for serius gamers that have build in heatsink
in them.

Those RAM sticks with heatsinks started because a lot of overclcockers were pushing up FSB speed, and in order to make the RAM work at higher speeds, they would up the voltage to the RAM.

In a lot of ways, its pointless to have heatsinks on RAM if you are not overclocking (or havent had the factory overclock or overvoltage the RAM, and yes, that does happen). But personally, I prefer heatsinked RAM, it makes it easier to work on. Its far harder to snap of a tiny capacitor on a RAM stick when the whole thing is encased in heatsink. :)

handy
December 16th, 2009, 12:28 PM
I really do understand the huge grey area surrounding electrical power usage.

How do we know how much energy any of the appliances in our house use unless we measure them. We just don't really know how much power our electronic/electrical devices use unless we measure their power usage.

This problem recently drove me to the point of buying a device that allows me to plug it in between the power point & the device who's power consumption/cost I am interested in.

The device is (quite appropriately I thought) called the Power-Mate.

I have now so far learned what my fridge, freezer, microwave's clock, clothes dryer, food dehydrator, PIII headless firewall, cost per hour/year to run. I'm still on the job, the monitor is currently on this computer so I will have good figures on it before too long as well.

If you are interested in these costs let me know & I'll spit them out here?

t0p
December 16th, 2009, 12:46 PM
I really do understand the huge grey area surrounding electrical power usage.

How do we know how much energy any of the appliances in our house use unless we measure them. We just don't really know how much power our electronic/electrical devices use unless we measure their power usage.

This problem recently drove me to the point of buying a device that allows me to plug it in between the power point & the device who's power consumption/cost I am interested in.

The device is (quite appropriately I thought) called the Power-Mate.

I have now so far learned what my fridge, freezer, microwave's clock, clothes dryer, food dehydrator, PIII headless firewall, cost per hour/year to run. I'm still on the job, the monitor is currently on this computer so I will have good figures on it before too long as well.

Boredom? OCD? Or is money too tight to mention?



If you are interested in these costs let me know & I'll spit them out here?

Ooh yeah! Please! :p

Grenage
December 16th, 2009, 12:50 PM
We did the same thing in our house, and were amazed how much energy some things were using... even when not in use!

E.G: over two years, a stereo on standby was costing about 80; a Kettle not in use was still drawing some power. Bottom line is that by studying how much power something is using, you can save hundreds of pounds per year.

3rdalbum
December 16th, 2009, 12:51 PM
RAM does not use a lot of power. Look - power equals heat. Your CPU needs an integrated heatspreader, a heatsink and a fan to disperse the power that is wasted as heat. Plus special thermal interface paste to ensure a good fit between the components.

By contrast, most RAM sticks get along fine with just their heatspreader. Even high-end overclocker RAM just uses a heatsink with no fan.

So no, your RAM sticks probably use less power than an Intel Atom CPU. Maybe a couple of watts per gigabyte. Not worth worrying about.

hobo14
December 16th, 2009, 12:55 PM
RAM has to use energy, what else is going to make it work?

http://www.computerforum.com/134016-memory-power-consumption-question.html

Just search the web a bit to find out about it, finding the above link took all of 2 minutes. :)

If you search a little longer, you should find more appropriate energy consumption values, as in they relate to today's technology.

You are omitting the massive read/write speed difference between RAM and disk.

If you compare the rates of energy consumption per megabyte read/written for disk and RAM, RAM will be vastly superior.

Hence, adding more RAM to your computer will lower your power consumption.

Please do not view this as an opinion, it is a fact. I will continue explaining in more detail if you like, but hopefully this is enough.

handy
December 16th, 2009, 01:20 PM
Boredom? OCD? Or is money too tight to mention?

Roughly a year ago we converted to an incredibly efficient solar hot water system, & we put 2kW worth of solar panels on the roof to generate electricity which is used first on our property then after that any excess is fed back into the grid.

That which is fed back into the grid we are credited for; starting on the 1st of Jan' we will also get 60 cents from the state government for every kW that we put back into the national grid.

So that might give you a slight impression as to why I want to know just what every electrical component in this house that I can measure's power consumption & cost is?

Beyond which you should know, that the impression that you now have gained with regard to my personal thoughts & motives apropos power usage & its measurement is naught but a mere shadow of the true reason why I have this desire. ;)



Ooh yeah! Please! :p

I'll post it here in this thread, but not yet, I've got some more data to collect, then I can throw it all out in one post, rather than fragmenting it.

Dragonbite
December 16th, 2009, 03:51 PM
So it sounds like a yes and no.

Yes it will consume more energy, but no because it reduces the use of physical components like disk spinning which uses more energy.

Anything that "moves" takes a lot of energy to run.

There is also the benefit of if the system is running faster, you'll be in-and-out faster than before and able to suspend to RAM/Disk or turn off quicker.

On laptops with disk drives I usually make them the boot device AFTER the hard drive. So the system boots from the hard drive and doesn't bother with the disk drive unless either the hard drive doesn't work or I hit F12 during bootup and select the disk drive that time around.

Paqman
December 16th, 2009, 04:39 PM
If you are interested in these costs let me know & I'll spit them out here?

I recently did a power audit myself, and it's definitely changed the way I do things. I wrote the whole thing up on my blog (http://andyduffell.com/techblog/?tag=home-power-audit), raw data is attached at the bottom of the first post.

cascade9
December 16th, 2009, 04:46 PM
@ handy- yes, I would like to see any hard data you have. Might be better to make a new thread IMO, but whatever you want (your the dude with the data LOL). BTW- I'd rather see it in kw/hrs rather than cost. Power costs vary worldwide, but kw/hrs doesnt ;)


You are omitting the massive read/write speed difference between RAM and disk.

If you compare the rates of energy consumption per megabyte read/written for disk and RAM, RAM will be vastly superior.

Hence, adding more RAM to your computer will lower your power consumption.

Please do not view this as an opinion, it is a fact. I will continue explaining in more detail if you like, but hopefully this is enough.

Its a fact.....if qualified a bit more than that. Just saying "more RAM = lower power consumption" is Not True.

Look at it this way- If you have a computer that uses 3GB maximum, and you have 2GB (thereby hitting swap pretty heavily), then yes- adding RAM will lower consumption.

However, if your max RAM uses is still 3GB, and you have 4GB (2x2GB sticks), and then change to 8GB (2x4GB sticks), your power consumption will possibly go up. Best case is consumption stays the same (unless you get RAM with a lower voltage, but lets ignore that LOL).

Besides, each RAM stick uses power, and adding sticks (which would be more common, people tend to just add sticks in most cases) and changing to 8GB (4x2GB) will use more power.

handy
December 16th, 2009, 04:47 PM
I recently did a power audit myself, and it's definitely changed the way I do things. I wrote the whole thing up on my blog (http://andyduffell.com/techblog/?tag=home-power-audit), raw data is attached at the bottom of the first post.

Yes, I agree, it is an eye opener.

Dragonbite
December 16th, 2009, 05:34 PM
With more RAM, try introducing an SSD instead of the hard drive and see the comparison!

Paqman
December 16th, 2009, 06:10 PM
With more RAM, try introducing an SSD instead of the hard drive and see the comparison!

Heck, do that even if you aren't worried about power use. SSDs are the way forward. There's no way i'm ever installing another magnetic hard drive in my machine.

Grenage
December 16th, 2009, 06:11 PM
They are, but they are also still incredibly expensive (unless you only have a few GB of data).

Gizenshya
December 16th, 2009, 07:13 PM
True, the RAM does need power. That link is amusing (128MB = 8 watts? OK. But that doesn't make 512MB = 32watts).

I reality, as far as I know, changing over sticks to bigger RAM sticks will use a bit more power, but its in the order of 10-20% or so, nothing major. Increases in power consumption from RAM would be offset by lower drive accessing (to a point anyway).



Those RAM sticks with heatsinks started because a lot of overclcockers were pushing up FSB speed, and in order to make the RAM work at higher speeds, they would up the voltage to the RAM.

In a lot of ways, its pointless to have heatsinks on RAM if you are not overclocking (or havent had the factory overclock or overvoltage the RAM, and yes, that does happen). But personally, I prefer heatsinked RAM, it makes it easier to work on. Its far harder to snap of a tiny capacitor on a RAM stick when the whole thing is encased in heatsink. :)

True on all counts.

It is worth noting, though, that the RAM in laptops is FAR more effecient than regular desktop RAM. For any given # of sticks, an increase in the available storage space does not necessarily increase power consumption. It is very possible to have a larger RAM module use less power. Size is not the only factor. But, if it is the same brand, and same 'line' of RAM modoles within that brand, then it will almost certainly use the same amount of electricity or a little more (not less). I would say a 10-20% increase is an overstatement, but it would still be useful to use that a a worst-case scenario. And that percentage only applies to the amount used by the RAM. On laptops, the vast majority of the energy is being consumed by the monitor. This can be easily seen on any laptop by simply watching the battery "till empty" time change dramatically if you adjust the brightness of the monitor. A 20% increase on something that only uses probably 10% of the power anyway still only amounts to a 2% power increase. If your battery usually lasts 2.5 hours (150 mins) that would mean about 3 mins less, if used until depletion. I think say that the actual decrease would be less than a minute, though.

Laptop RAM modules rarely have heatsinks. They use less power (thus emmit less heat), and they usually aren't overclocked.

Also, RAM would only decrease hard drive useage if the 2gb already causes a lot of SWAP activity. Unless you have a gaming rig, running bloated Windows 6 or later, your SWAP probably remains a barron landscape, even with 2GB of RAM. Unless you do serious graphic work in ubuntu, I can't see any advantage of having 4GB of RAM. In your system monitor, do you often see the swap having used space? If you do and it slows your system, then it might be justified, but elseif not IMO it would be a waste of money. But it wouldn't be a significant impact on battery life.

Sinkingships7
December 16th, 2009, 07:41 PM
I'll admit that I only skimmed the responses here, but I saw a lot of very misguided posts.

It's as simple as this: The more memory modules you have installed, the more power it will draw from the PSU. A 1GB stick of DDR2 memory will draw the same amount of power as a 2GB stick. Generally around 1.8 to 2.1 volts these days.

2 x 2GB memory modules will consume HALF the power as 4 x 1GB modules.

Keep in mind that AMD's processors (of which I am a fan) have a hard time with more than two sticks of memory. Not in terms of power, but in terms of controlling the memory bandwidth. Remember that the memory controller is built into the newer processors these days, instead of on the motherboard. So if you have an AMD system, try to keep it down to two sticks.

From what I've heard, Intel doesn't have this issue.

Also worth noting, DDR3 memory draws less power than DDR2 memory (around 25%), so if you want a lot of memory, that may be the way to go. HOWEVER, do not ignore the importance of latency. Many people are fooled by thinking faster clock speeds == faster memory. This is not always the case. 2 x 2GB of DDR3 memory running at 1600MHz with CAS 10 timings is not going to be faster than 2 x 2GB of DDR2 memory running at 1066 MHz with CAS 5 timings.


This post is getting long, so I'll leave it at that. Feel free to ask questions.

Paqman
December 16th, 2009, 08:11 PM
They are, but they are also still incredibly expensive (unless you only have a few GB of data).

You can keep your data on an old-fashioned drive if you need storage. 64GB or 80GB SSDs are starting to get down to reasonable prices, and are big enough for even the bloatiest operating system.

IMO they're now getting down to the point where the price is justified for the massive jump in performance. If you were thinking of upgrading your machine, throwing 150-200 at an SSD will give you a bigger boost than throwing that same amount into CPU/mobo/RAM.

Firestem4
December 16th, 2009, 08:31 PM
Power consumption is not linear. As the link provided, 128mb=8 watts, yes. But 256!=18 watts. The amount of capacity does not have a directly porportional value to energy consumption.

Also the reason why RAM takes up so much is because DRAM (the most commonly used ram in the world) must refresh itself every cycle to retain the memory, otherwise it is lost. Otherwise SRAM, (static Ram) which is slower, does not use energy to maintain data. But people trade power for speed.

SOrry if the point has been made already. I'm feeling lazy today and didn't read all of the posts.

Dragonbite
December 16th, 2009, 08:33 PM
You can keep your data on an old-fashioned drive if you need storage. 64GB or 80GB SSDs are starting to get down to reasonable prices, and are big enough for even the bloatiest operating system.

IMO they're now getting down to the point where the price is justified for the massive jump in performance. If you were thinking of upgrading your machine, throwing 150-200 at an SSD will give you a bigger boost than throwing that same amount into CPU/mobo/RAM.

Plus, if you get a new machine it is easier to move a SSD/HD from one machine to another than it is to hope the RAM/etc. is compatible.

hobo14
December 17th, 2009, 09:19 AM
@ handy- yes, I would like to see any hard data you have. Might be better to make a new thread IMO, but whatever you want (your the dude with the data LOL). BTW- I'd rather see it in kw/hrs rather than cost. Power costs vary worldwide, but kw/hrs doesnt ;)



Its a fact.....if qualified a bit more than that. Just saying "more RAM = lower power consumption" is Not True.

Look at it this way- If you have a computer that uses 3GB maximum, and you have 2GB (thereby hitting swap pretty heavily), then yes- adding RAM will lower consumption.

However, if your max RAM uses is still 3GB, and you have 4GB (2x2GB sticks), and then change to 8GB (2x4GB sticks), your power consumption will possibly go up. Best case is consumption stays the same (unless you get RAM with a lower voltage, but lets ignore that LOL).

Besides, each RAM stick uses power, and adding sticks (which would be more common, people tend to just add sticks in most cases) and changing to 8GB (4x2GB) will use more power.

Yes, quite true, I should have been more specific: "if you're already using all your RAM". I just assumed this was the case, else there's not much reason to buy more RAM.
Apologies ;)



I'll admit that I only skimmed the responses here, but I saw a lot of very misguided posts.
I assume you aren't including mine in that statement? Hard to tell your meaning here, not sure whether to argue with you or not...

Grenage
December 17th, 2009, 09:37 AM
You can keep your data on an old-fashioned drive if you need storage. 64GB or 80GB SSDs are starting to get down to reasonable prices, and are big enough for even the bloatiest operating system.

That I agree with, putting the OS on a relatively small SSD drive is a great performance boost, and not too pricey.

Exodist
December 17th, 2009, 09:37 AM
if i upgrade my laptops ram from 2gigs to 4gigs, but if the amount of sticks i put in the mobo doesnt change, would my laptop be using more power?
This is a triple edged question with many variables.

IF (Your System) = (Thrashes HDD constantly + Has Power saving enabled)
Then = Installing more RAM will lower over all system wide power consumption.

IF (Your System) = (Thrashes HDD constantly + Does not have power saving)
Then = Installing more RAM may not raise nor lower the over all system wide power usage.

IF (Your System) = (Does not Thrash HDD constantly, regardless of power saving settings)
Then = Your over all system wide power consumption will raise.

ssam
December 17th, 2009, 12:11 PM
there are 2 ways that more ram will reduce harddisk usage.
* less swapping
* more disk caching

also note that voltage does not tell you the power consumption. power is voltage x current (strictly only true for DC circuits, but good enough here). so just because 2 modules run at 1.8 V, does not mean they will use the same power.

In some cases you will find for example that a 1GB module has 8 chips on it, and a 2GB from the same manufacturer has 16 of the same chips. in this case power usage will probably scale with size. Other times the 2GB might be 8 chips each with higher data capacity.

this page has data sheets for all kingston's RAM modules, which give the power usage
http://www.valueram.com/datasheets/default.asp
there is quite a big range.

gnome-power-statistics should be able to tell you how much power your laptop uses (you may have to run on battery to get a number).

Sinkingships7
December 17th, 2009, 02:12 PM
I assume you aren't including mine in that statement? Hard to tell your meaning here, not sure whether to argue with you or not...

No, your posts were fine. I didn't mention anything about hard drives, but it's true that having more RAM lessens the chance of disk access (swapping), which can, in turn, save more power. I don't consider getting anything less that 4GBs these days, but depending on what the OP does, 2GB may be plenty.

hobo14
December 17th, 2009, 04:04 PM
This is a triple edged question with many variables.

1. IF (Your System) = (Thrashes HDD constantly + Has Power saving enabled)
Then = Installing more RAM will lower over all system wide power consumption.

2. IF (Your System) = (Thrashes HDD constantly + Does not have power saving)
Then = Installing more RAM may not raise nor lower the over all system wide power usage.

3. IF (Your System) = (Does not Thrash HDD constantly, regardless of power saving settings)
Then = Your over all system wide power consumption will raise.

You can discount 3; if this was the case he wouldn't be buying more RAM.


I'd like to hear your justification for 2.

It is incorrect. If you add more RAM, some disk accesses are replaced by RAM access, power consumption will drop (assuming the system was attempting to use more than the available RAM in the first place).
No power saving function will change this.

Dragonbite
December 17th, 2009, 04:13 PM
This is a triple edged question with many variables.

IF (Your System) = (Thrashes HDD constantly + Has Power saving enabled)
Then = Installing more RAM will lower over all system wide power consumption.

IF (Your System) = (Thrashes HDD constantly + Does not have power saving)
Then = Installing more RAM may not raise nor lower the over all system wide power usage.

IF (Your System) = (Does not Thrash HDD constantly, regardless of power saving settings)
Then = Your over all system wide power consumption will raise.

Wouldn't a CASE statement be slightly more efficient?

:lolflag:

benj1
December 17th, 2009, 04:37 PM
Wouldn't a CASE statement be slightly more efficient?

:lolflag:

might be python, maybe else ifs as theyre all mutually exclusive

Dragonbite
December 17th, 2009, 04:49 PM
might be python, maybe else ifs as theyre all mutually exclusive

No CASE statements in Python?

-grubby
December 17th, 2009, 05:20 PM
No CASE statements in Python?

Python doesn't have a case statement, correct.

Exodist
December 17th, 2009, 06:15 PM
You can discount 3; if this was the case he wouldn't be buying more RAM.

I'd like to hear your justification for 2.
I cant help you if your not mentally incapable of understanding basic power usage.
Read it again, youll get it.. Else = (play in middle of road).

Exodist
December 17th, 2009, 06:16 PM
wouldn't a case statement be slightly more efficient?

:lolflag:


lol :)

hobo14
December 17th, 2009, 10:18 PM
I cant help you if your not mentally incapable of understanding basic power usage.
Read it again, youll get it.. Else = (play in middle of road).

What an incredibly rude post. I hope that makes you feel proud.
I take it to mean you can't back your little claim up with any facts.

You are completely incorrect on point 2; it doesn't matter whether you are using power saving features or not, adding RAM to a system continuously swapping memory to disk will reduce power consumption.

Simply, more RAM means less swapping, so less use of the disk.
Some disk access is replaced with RAM access.
Thanks to the fact that accessing X amount of data in RAM uses far less energy than accessing X amount of data on disk, power consumption drops.
Under no circumstances will any power saving features change this.

Try knowing what you're talking about before you open your mouth.

Chronon
December 17th, 2009, 11:01 PM
I cant help you if your not mentally incapable of understanding basic power usage.
Read it again, youll get it.. Else = (play in middle of road).

You should double-check your syntax (and grammar) when attempting to rip someone a new one. You didn't say what you meant to say.

hobo14
December 18th, 2009, 07:21 AM
I'd like to hear your justification for 2.

No answer to the challenge Exodist? I'm not surprised. Your claim was unjustifiable; power consumption will drop regardless of power saving settings.

hobo14
December 19th, 2009, 02:22 AM
did i make the ram power consumption thread too scary to come back to? So sorry.

I don't expect you to try and defend the indefensible, but just in case you feel like actually spitting out even the tiniest bit of logic that backs up your point there, feel free to share it with us all.
Don't worry, i won't bite.

its no biggy.. Lol
i thought i was pretty clear and sometimes its very hard for me to explain or debate something. I would make a horrid teacher. So to keep from getting frustrated i just sometimes walk away.
Perhaps next time you will educate yourself on a subject before making wild claims in relation to it, and temper your responses when you are challenged.