# How important is it to pair RAM?



## smoothjk

Hi all,

Last night, I ordered four sticks of RAM to put into my computer ("upgrading" from PC2 4200 to 5300, 533 to 667).

Problem is, I found out today that I can only have three, as they're out of stock.

Now, I know it's best to pair them, but since I can only have three for the time being, my questions are as follows:

- Should I just put in two of the sticks for now and leave the third out until the fourth one gets here?
- Should I put all three in now, knowing that the third one would be better off paired, but it's still better than not having it in there at all?
- Should I just leave it at 3GB and never order the fourth when it's in stock, knowing that Windows XP 32-bit is not really going to recognize 4GB anyway?

Please chime in with your thoughts. Thanks guys!


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## Quiltface

Does your mobo even support pairing?  what mobo do you have?


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## smoothjk

Oh, I didn't realize my mobo had to support it. I've just always heard that it's best to buy RAM in pairs.

If it's some kind of advanced feature, chances are, my mobo doesn't have it. It's not exactly top of the line:

http://www.fic.com.tw/product/motherboard/AMD/k2bc51lf.aspx


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## Iced_Bullet

What's your budget and what size do you want because it sounds like you're replacing the existing ones ... so you could get the same memory size, but in 2 sticks compared to 4.


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## houseofbugs

smoothjk said:


> Oh, I didn't realize my mobo had to support it. I've just always heard that it's best to buy RAM in pairs.
> 
> If it's some kind of advanced feature, chances are, my mobo doesn't have it. It's not exactly top of the line:
> 
> http://www.fic.com.tw/product/motherboard/AMD/k2bc51lf.aspx



Its properly called "Dual Channel". This was first introduced with the Pentium 4 and Athlon XP chips. It provided better performance by 'grouping' the ram. Each stick has a 64-bit bus and when dual channel is enabled it basically treats the two sticks as one only with way more bandwidth.

EDIT: Wow that is a very off brand of motherboard. I have never heard of it until now.

~Tim


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## smoothjk

houseofbugs said:


> Its properly called "Dual Channel". This was first introduced with the Pentium 4 and Athlon XP chips. It provided better performance by 'grouping' the ram. Each stick has a 64-bit bus and when dual channel is enabled it basically treats the two sticks as one only with way more bandwidth.
> 
> EDIT: Wow that is a very off brand of motherboard. I have never heard of it until now.
> 
> ~Tim



So basically, this RAM would work better in pairs (http://www.newegg.com/Product/Product.aspx?Item=N82E16820144233) but these might not? (http://www.newegg.com/Product/Product.aspx?Item=N82E16820144807)

Going back to my original questions, what's the best course of action here, judging from the info available? Please let me know, thanks.


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## smoothjk

Oh wait, this is a motherboard issue, right?

So does that mean it doesn't matter if I buy dual channel RAM or if I buy it in pairs? Because I don't see anything in my motherboard's specs about supporting dual channel. Still feeling quite lost here...=/


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## StrangleHold

There is no such thing as Dual Channel Memory. The Memory Controller runs the memory in Dual Channel. A matched pair always runs more stable in Dual Channel. If they sell it in pairs it just means they were tested and guaranteed to run together. The same ram sold separate (singles) will run in Dual Channel. On that AMD the memory controller will kick it out of Dual Channel if you run 3 sticks. It will only run in Dual if you have 2 or 4 matching sticks.


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## Quiltface

your mobo *requires* you to install in pairs... no choice.

Also its max is 4GB   DDR2 PC2-4200/5300/6400  NON-ECC


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## tyttebøvs

Quiltface said:


> your mobo *requires* you to install in pairs... no choice.



How do you figure that?


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## smoothjk

Thanks guys for the info. As it turns out, some diagnostic program that measure CPU temp/speed and memory shows that my RAM is currently running in dual channel.

So I guess I should put 2 of the sticks in now and wait for the last one to arrive?


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## Quiltface

tyttebøvs said:


> How do you figure that?



Looked it up on www.crucial.com


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## StrangleHold

Quiltface said:


> your mobo *requires* you to install in pairs... no choice.
> 
> Also its max is 4GB DDR2 PC2-4200/5300/6400 NON-ECC


 
It requires you to run two sticks to run in dual channel, but you can install just one stick and it will run just fine. But in single channel.


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## Quiltface

they are liars?


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## StrangleHold

Who are are liars? There has never been a AMD board (ever)all the way back to from there remake of the Intel 8080 to the Phenom that would not run with just one stick of memory. True you have to have 2 sticks to run in Dual Channel, but any board does.


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