?
Solved

Dual Rank Memory - Is there a performance advantage?

Posted on 2007-07-24
7
Medium Priority
?
7,203 Views
Last Modified: 2013-11-10
Hi - I know there are already a few threads relating to the single vs dual rank memory arguement but can anyone tell me if there is any performance benefit in using dual rank memory in a server.

I am speccing a large server to run SQL Server 2005 and need to know whether to go for the dual rank memory.

The single is cheaper but cost is not relevant. I need to be able to deliver best performance.

Thx...
0
Comment
Question by:stevemjp
6 Comments
 
LVL 63

Expert Comment

by:SysExpert
ID: 19556338
It depends on the Server hardware, and whether it supports 2 DIMMS to increase speed.

Check the Server specs. In general I have not seen this. so I would not bother.


I hope this helps !
0
 
LVL 70

Expert Comment

by:garycase
ID: 19559672
The maximum performance of your memory subsystem is achieved if you utilize all four ranks in each memory channel.   Whether you do this with four single-rank DIMMs, or two dual-rank DIMMs doesn't matter.   So the answer to your question depends on the memory configuration you're using.  

If your system supports dual channel memory, then you want to have 4 ranks in each channel ... in this case that's often achieved by using four dual-rank DIMMs (two for each channel).

Do NOT, however, mix single and dual rank DIMMS ... that will tend to reduce performance, as the chipset will not be able to uniformly distribute addresses.

0
 
LVL 56

Expert Comment

by:andyalder
ID: 19620732
I don't see why you shouldn't mix ranks; say you have 6 slots of interleaved RAM available on the motherboard, one dual rank 4GB pair plus two single ranked 2GB pairs does uniformly distribute the memory surely?
0
VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

 
LVL 2

Expert Comment

by:JaneArcher1
ID: 19744687
i think garycase ment dont mix duel and single rank in paired slots.

most MB that have say 4 memory slots will have 1 and 3 and 2 and 4 as seperate channels.

so if you put memory in slots 1 and 2 they will run as single channel mode. however if you put the same modules in slots 1 and 3 they will run duel channel.

however you should not mix single and duel channel modules in the same MB channel :)

so you could have single rank pairs in slots 1 and 3 and duel rank modules in slots 2 and 4 and be ok.

but not single modules in slots 1 and 2 and dule modules in slots 3 and 4. as this would result in mismatched pairs and reduce proformance.
0
 
LVL 56

Accepted Solution

by:
andyalder earned 750 total points
ID: 20645630
It's pretty much irrelevant now since bank interleaving depends on the motherboard and they have changed quite a bit in the last 6 months. Delete is fine by me.
0
 
LVL 70

Assisted Solution

by:garycase
garycase earned 750 total points
ID: 20645652
The interface technology hasn't changed --- it's still faster to use fully populated channels (four ranks in each channel).   My original answer is still correct ... but I really don't care if the question is simply deleted or not => although, as always, it would be best if stevemjp would return and either select the answer he found most useful, or ask that the question be closed if he didn't find the information useful.

0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

pc, laptop  monitor connection configurations
Arrow Electronics was searching for a KVM  (Keyboard/Video/Mouse) switch that could display on one single monitor the current status of all units being tested on the rack.
this video summaries big data hadoop online training demo (http://onlineitguru.com/big-data-hadoop-online-training-placement.html) , and covers basics in big data hadoop .
This video shows how to quickly and easily deploy an email signature for all users in Office 365 and prevent it from being added to replies and forwards. (the resulting signature is applied on the server level in Exchange Online) The email signat…

829 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question