# nehalem memory configuration

## aZZe

Howdy y'all!

Does anyone of you know an official document that describes the memory misconfiguration with Intel Nehalem CPUs? For example what is the performance impact choosing just two memory modules instead of three? I searched the internet but couldn't find a site that can tell me exactly how much impact I can have with only one or two used memory channels instead of three. 

Any help would be appreciated. 

Thanks!

----------

## Yuu

Hi aZZe,

I found this one : http://www.insidehw.com/Reviews/Memory/Intel-Core-i7-Dual-Channel-vs.-Triple-Channel-Memory-Mode.html

But as far as I know, tripple channel gives you more performance with more cores in your CPU. For example, tripple channel will gives you more performance with a 6 cores CPU, than with a dual core (source in french, or in english with google).

But with the results that we can see, tripple channel doesn't gives yo a huge performance boost.

----------

## aZZe

Hmm this is not what I mean. My main focus are Xeon Processors X7500 series. I don't think you have the possibility to change from dual channel to triple channel with those CPUs. I found a site that explains it pretty good:

http://www.delltechcenter.com/page/04-08-2009+-+Nehalem+and+Memory+Configurations

I know that the DIMM's speed goes down to 800MHz when you use a lot of RAM but that's not my question. The question is what is the performance impact by just using one or two DIMMs? 30% or up to 50% or more???

----------

## dmpogo

For most people, me include,d Nehalem is associated primarily with i7 processors  :Smile: 

----------

## aZZe

I know. But possibly here are some guys who have experience with Xeon processors.

----------

## TJNII

So are you talking about the memory controllers or the DIMMS themselves?

----------

## aZZe

First of all the memory controllers. As you know the new Nehalem Xeons have three instead of two memory controllers.

----------

## TJNII

Well, it just so happens that Dell has a whitepaper on this very subject.

http://www.dell.com/downloads/global/products/pedge/en/poweredge-server-11gen-whitepaper-en.pdf

This paper is about machines with Millbrook memory buffers, which seem to be very popular nowadays.

----------

