Hi there!

 

This is my first question but I've been lurking on here for about a week or so, but I do apologise in advance if my question seems really dumb or the answer could be found somewhere else!

 

So I've recently got up and running with a ThinkSystem SR630 (7X02), which came with a base config of 16GB of Memory. The stick that's installed is a DDR4-2666 2RX8, and slowly I'd like to build out with more memory as I go along.

 

The Maintenance Guide, Setup Guide, the Quick Start Guide for the SR630 and the document from Lenovo Press called "Memory Population Requirements for Lenovo ThinkSystem Servers"  all say that the "type of DIMMs can't be mixed" but it always appears in the context of the "type" of DIMM such as RDIMMs, LRDIMMs and 3DS RDIMMs. I couldn't find anything that specifically refers to the rank of the memory being mixed.

 

So basically my question is: Am I able to use the 2RX8 module that came with the server along side 2RX4 modules?

 

Hope it's not too silly! Thanks everyone.

Hi Matty
From Lenovo Japan

 

Thank you for your participating in our forum site.

 

When doing any kind of Parts confirmation the
quickest way is to use the below site and simply put in your serial #
and it will direct you to a filtered and customized dashboard
just for your unit and look through the different tab for Documents.

 

https://datacentersupport.lenovo.com

 

http://thinksystem.lenovofiles.com/help/index.jsp?topic=%2F7X01%2Fpdf_files.html

 

From the above link

This is the statement from Lenovo

 

Answer: Note: It is recommended to install DIMMs with the same rank in each channel.

ThinkSystem rack servers > ThinkSystem SR630 Types 7X01, 7X02 > Hardware replacement procedures > DIMM replacement
DIMM installation rules
DIMMs must be installed in a specific order based on the memory configuration that you implement on your server.

Your server has 24 DIMM slots and it has the following features:
Each slot supports 8 GB, 16 GB, and 32 GB DDR4 RDIMMs with Error Checking and Correcting (ECC) technology.

Each slot supports 64 GB DDR4 LRDIMMs with ECC technology.

Each slot supports 128 GB DDR4 3DS RDIMMs with ECC technology.

Your server supports up to 12 DIMMs when one processor is installed, and up to 24 DIMMs when two processors are installed.

The minimum system memory is 8 GB (only one processor installed and only one 8 GB RDIMM installed in the CPU1 DIMM5 slot).

The maximum system memory is as follows:
768 GB using RDIMMs (two processors installed and one 32 GB RDIMM installed in each of the 24 DIMM slots)

1.5 TB using LRDIMMs (two processors installed and one 64 GB LRDIMM installed in each of the 24 DIMM slots)

3 TB using 3DS RDIMMs (two processors installed and one 128 GB 3DS RDIMM installed in each of the 24 DIMM slots)

For a list of supported DIMM options, see:the Lenovo ServerProven website

Before installing a DIMM, ensure that all DIMMs to be installed must be the same type. Your server supports the following types of DIMMs:
DDR4 RDIMM with ECC technology

DDR4 LRDIMM with ECC technology

DDR4 3DS RDIMM with ECC technology

Note: It is recommended to install DIMMs with the same rank in each channel.

 

Hope this info helps.

 

Thank you for using this site.

Lenovo - Japan

Hey @OrientExpress, I really appreciate your reply.

As I mentioned in my original question, I did take a look at all of the documents you referenced. I even included a screenshot of the Maintenance Guide for the SR630 which happened to be exactly the paragraph you quoted hehe.

Don’t get me wrong, I’d love to do nothing more than specifically buy parts listed on the ServerProven site.

(which just so happens to be down right now, or is at least giving me “Our Apologies! We seem to be experiencing site issues.”)

Unfortunately here in Australia, Lenovo’s own OEM-branded Memory is almost double the price of memory bought directly from other memory manufacturers.

But your answer was certainly helpful and instructive - I completely missed the recommendation in the maintenance guide that DIMMs of the same rank (not type) should be used together in the same memory channel.

To me at least, that recommendation indicates that technically yes I can use DIMMs of differing ranks (again, not mixing DIMMs of different types) so long as those DIMMs are in different memory channels.

Could you at least confirm for me that this would work? I get it might not be recommended, but our budget is tight at the moment and there’s a limit to how much I can spend on this project at the moment.

Dear Valued customer,

 

Hi Matty

 

When looking at one of major Memory device manugactures site
they do have a way to put in your Lenovo Server and Model type
from there,

you will see approved memory from those manufactures.

Therefore from such site,

 

The items are listed as Lenovo ThinkSystem SR630
compatible. 

 

As long as you are not mixing manufactures and following
the no mix rule,

I would comment that it will work as the memory
for the specific server model is listed as "Compatible".

 

Thank you for participating in the Lenovo Forum Section.

Lenovo - Japan