# Dual channel memory, different sizes



## AmericanWaste (Sep 1, 2005)

Hello,

I am current running 2x256 in dual channel mode. I was about to make an uprade for some more ram. 

I was wondering if I needed to only purchase another set of 2x256, or if can I use 2x512 for the other channel. 

My mobo manual said to use same size DIMMs for each channel. I didnt know if they meant within each channel, or for both channels. 

Thanks for your time.


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## Tumbleweed36 (May 14, 2005)

Hi,

You need to use the same size, speed, model, and latency for the modern motherboards. They mean literly what they said, for each (all) channel(s). Mix matches just do not do the job and create many errors if they work at all. Most newer motherboards just will not work with a mixed pair.


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## AmericanWaste (Sep 1, 2005)

thanks, 

i guess i coulda just asked, 

do all *4* slots need to be the same size, less words :doh:


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## Tumbleweed36 (May 14, 2005)

Hi,

You did fine. Stay around the forum and jump right in any time you have a question or can help. Nice to see you here.


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## crazijoe (Oct 19, 2004)

When you buy memory for a dual channel MB, make sure you buy dual channel kits. Do not buy individual sticks because they might not match.


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## bill gisse (Aug 17, 2005)

Confused. Have a similar question but answers above aren't clear to me. I have two OEM 256's in a dual channeel configurationn for a total of 512. Can I put put two matched 512's in the two remaining empty sockets for a total of 1.5 g?Know I can do it but will a set up like this work right.


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## AzzKikr86 (Jan 28, 2009)

Everyone on here seems to be confused. A "channel" in a dual channel setup is the two slots that are combined to use a single channel for their data. Hence if your motherboard manual says they must be the same chips in one "channel" you only need identical sticks for that specific "channel". NOW, that does NOT mean you need ALL of the sticks to be identical... Anyone who would say that you always need all sticks exactly the same should not be submitting any form of advice on this forum. ( And I realize I've just joined this forum, but I am not lacking in knowledge, I've been doing this for 15 years now. ) 

So to answer the initial question: YES you can use the 2x512 setup on one channel, and the 2x256 on another channel, so long as the two new sticks you add are identical.


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## AzzKikr86 (Jan 28, 2009)

And I am aware of how long it's been since anyone posted, I'm just here incase someone comes along from google and is led astray because of ill informed/ignorant advice


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