2DIMMS vs 4DIMMS, Which RAM configuration is best?

I've never really understood the nitty gritty details on selecting the right combination of RAM, but as I'm considering an Alienware M17Xr3 for my next purchase, I'm honestly stuck in what I should choose.

First of all, how many DIMMS? 2 or 4? Is there a noticeable difference in performance between say, 2x4gb and 4x2gb? (Assuming 8GB is the max amount of RAM I would want to have, no upgrading in the future)

Also, for the new i7-2720qm processor, is there a "sweet spot" for the amount of RAM (6GB vs 8GB)? Currently, on the Dell site, they're offering 6GB (2DIMMS, meaning 3GB each stick) as default, and 8GB (4DIMMS, meaning 2GB each stick). Are there any rules in choosing RAM where "even" number configurations are better than "odd" number configurations?

Any help would be appreciated

 

RAM does not come in 3GB sticks. 6GB would come with one 4GB and one 2GB. RAM comes in 2^x sizes, and years ago used to come as small as 1MB, 2MB, 4MB, 8MB, 16MB ... to now these days it's pretty much 1GB, 2GB, or 4GB.

Also 2 sticks or 4 sticks doesn't matter much these days. The biggest advantage of fewer sticks is ability to easily upgrade later without having to dispose of memory. So if you have 2x2GB now, you could add 2x2GB later instead of having 4x1GB now, and having to remove all the 1GB modules to get 8GB in your system.

The price difference between 4 sticks and 2 sticks is nearly negligible too.

 

Thanks for pointing that out never knew that.

If the configuration doesn't really matter then, would you say that 8GB is enough for a processor like the 2720qm? Would something like 16GB be overkill for tasks such as moderate gaming, Cinema 4D rendering, Photoshop CS5?

And how about 1333mhz vs 1600mhz frequencies? I read that 1600mhz is only if I'm overclocking my CPU.

Lots of questions, but thanks in advance

 

Might as well just go for the 2x 4gb sticks in my opinion, as it will leave you with more headroom if you ever want to upgrade in the future. If you don't want to, then nothing is lost. As far as I know, the performance should be about the same regardless of if you have 2 sticks of 4gb, or 4 sticks of 2gb. Although, I'm no expert on the matter, and could easily be wrong.

 

8GB should be enough but as stated I'd still get 2x4GB in case you ever need more. Memory speed doesn't matter and it's really used as a marketing tool. Even if your CPU supports 1600MHz memory, you won't see any benefit when compared to 1066MHz. I'd only get the faster memory if it were cheaper or at the same price.

 

The problem with that is Dell only offers these configurations:

- 4gb 2DIMMS (2x2gb)
- 6gb 2DIMMS (1x2gb + 1x4gb)
- 8gb 4DIMMS (4x 2gb)
- 16gb 4DIMMS (4x 4gb)

If there was a 8gb 2DIMMS option, my decision would be a lot easier, but I'm guessing the 8gb 4DIMMS solution saves Dell money. Though, I noticed companies such as Sager/Asus offer 8gb in the 2DIMMS option.

 

That's just stupid. In that case, I would just get the 4GB and buy your own 2x4GB sticks which you can get for like $80-$85 these days.

Dell must just have a surplus of 2GB DIMMS.

 

Wrong.


Core i7 X58 Triple channel DDR3 memory kit list | i4memory.com

3 DIMM kits like this have been out since Intel introduced its X58 chipset with triple channel memory (nov 2008).
Although the only laptop that supports triple channel memory is the Clevo X7200.

 

^Note: That is desktop 240pin memory.

AFAIK though, there's been no laptop that's had an X58 chipset.

I've never seen a 3pk of notebook DIMM's.

 

Clevo X7200. Although yes, I haven't seen 3 dimm laptop kits either. Probably because only one laptop supports it.

 

I said no 3GB sticks.

Triple Channel uses 3 sticks, dual channel uses two. Only original desktop i7's were triple channel, I believe Sandy Bridge ones moved back to dual channel anyhow.

 

yep they did move back to dual channel since they are supposed to replace the lga 1156 chips not the lga 1136, the latter is going to be replaced with the lga 2011 which should support quad channel memory. Basically this is intel releasing server parts on the consumer market

 

16 GB is overkill for the gaming, might or might not be for the rendering or photoshop, depending on how big your projects are (and how much processing you're doing).

You won't typically notice the difference in speed between 1333 MHz and 1600 MHz, although 1600 MHz can give you a little more headroom if you're manually overclocking (also depending on how you overclock). Note that you usually won't be able to manually overclock an i7-2720QM, so the point is somewhat moot.

 

While most memory these days is sufficient, I have run into issues with mixing memory brands as a matched pair. Better of buying your own and selling whatever comes with your laptop.

 

HTWingNut,

My experience too: match RAM leads to much better (read: stable) systems. Contrary to what the nominal spec's might lead us to believe.

 

I'd get 4 2GB sticks. Seriously , 8GB is more than enough. I rather have 4 sticks than 2 4GB sticks just in case one of your RAM modules i faulty. Than your only 2GB down..

 

Oh come on, dont confuse people.