Poweredge R610 Mixed Memory

Question

Does anyone know if it is recommended to mix the sizes of memory dimms on R610s?

I have a pair of R610s and a hand full of 4GB and 8GB dimms that I would like to spread evenly between the 2 to give them each 40GB.

Daniel My · Accepted Answer

Hello Mike

I wouldn't say it is recommended, but it will work. The only problem with mixing memory is that you will not be able to populate the third channel. It will make slots A3,A6 - B3,B6 unusable.

The rules to keep in mind would be to put the larger memory in the first slots
DIMMs must be installed in pairs at minimum unless booting to a single DIMM in A1 for testing
The two lanes must match

I would populate it something like this:

8GB - A1,A2,B1,B2

4GB - A4,A5,B4,B5

I can't think of a way off the top of my head to hit 40GB. If you are only running a single proc then you would populate it like this:

8GB - A1,A2

4GB - A4,A5

If there are any questions let me know.

Thanks

Daniel My · Accepted Answer

Hello igmac

With 8x4GB and 4x8GB modules available the maximum configuration would be this:

A1/B1: 8GB
A2/B2: 8GB
A4/B4: 4GB
A5/B5: 4GB

Available memory will be 48GB unless my math isn't working this morning. If you had 2 more 8GB DIMMs then you could populate the third slot on each side; excluding limitation on quad rank and other restrictions on using the third slot.

Thanks

igmac · Accepted Answer

Thank you for that Daniel.

We just finished upgrading the 2 servers with the memory as given above a few minutes ago. I tested the various possible memory configurations, and can confirm that your answer above works perfectly.

I couldn't find where to 'accept' your answer and to mark the question as answered though. Could you possibly do that? Keep the forum nice and tidy :-)

In the end, because we had 2 servers, both with 4 x 4g x 2 processor banks (8 x 4g in total) per server, I configured one server with 4 x 8g per processor bank (64g total) and set it to Advanced ECC mode (8g's were in slots 2,5,3,6 with 1,4 empty as per manual).

For the 2nd server we used the spare memory modules and put 4g modules into every slot, giving 48G. This one was configured in Optimizer mode, again as per manual.

FYI, I also tested with:

A1/B1: 8G

A4/B4: 4G

A2/B2: 8G

A5/B5: 4G

This you told us would work and we confirmed it - and then also added:

A3/B3: 4G

A6/B6: 4G

You said it would work on 8G/8G, not with 4G/4G but we tried it anyway. This actually did work, BUT was flagged as an "Unsupported Memory Configuration" and gave the "F1 to continue" message. I assume that the memory in this configuration would have been in a very low performance mode or something like that. I suppose that in a pinch you might be able to use it like this (home server anyone?), probably by disabling the "F1 to continue" option in the BIOS.

Thank you very much for your assistance.

Regards,

Ian.

igmac · Answer

I've got an almost identical situation, where we have existing 4G x 8 modules on two processors.

We're wanting to install another 8g x 4 modules to max out the memory sockets.

From what you write above, you say we would not be able to populate the 3rd channel and would have to remove those 4g modules from A3, A6 and B3, B6 and instead of going from 32G to 64G we would only get it up to 48G max by mixing 8g and 4g memory modules? Ours is a R160 btw.

We've already noted that the system will have to move from Advanced ECC mode into Optimizer mode.

Daniel My · Answer

Thanks for the update!

I-Jen · Answer

On the same line of questions:

We have a R610 with 6 x 2GB for a total of 12GB. If I need to double the RAM to 24GB, here are my options:

1. Add 6 x 2GB

2. Add 3 x 4GB (I'm not sure this will work)

3. Replace all 2GB with 6 x 4GB

Or are there other options I can consider.

Thanks

Daniel My · Answer

Hello i-jen

1. Add 6 x 2GB

If you have two processors(Which I'm guessing you do or you would not have 6 available slots) then yes this will work.

2. Add 3 x 4GB (I'm not sure this will work)

This will not work in a 2 CPU configuration. Each lane(A lane and B lane) must have an identical memory configuration. There is not a way to split 3 DIMMs evenly across the two lanes. You would need to add 6. Our 11th generation servers do not allow flexible memory configurations, so if you have 3 DIMMs populated in bank 1(slots 1-3) then you can only populate bank 2(slots 4-6) with 0 or 3 DIMMs. You would not be able to populate 1 or 2 DIMMs in those banks. Aside from that you would also need to match the B side(Lane 2) with the same DIMM configuration.

3. Replace all 2GB with 6 x 4GB

Yes, that should work as well.

Thanks

I-Jen · Answer

I ended up purchasing 4 additional RDIMM of 8GB each thinking just swapping out the 2GB sticks and replace with 8GBs. However, after speaking to tech support, I was told there shouldn't be a problem mixing the two.

In Advanced ECC mode, I could put the 8GB in slots A2/B2 & A3/B3 and 2GB in A5/B5 & A6/B6.

In Optimized mode, which should be the default when the server was shipped, I can have the 2GB in A1/B1, A2/B2 & A3/B3 and 8GB in A4/B4 & A5/B5. This will yield 44GB total, a good addition for a server running SBS2011.

Thanks

Daniel My · Answer

In Optimized mode, which should be the default when the server was shipped, I can have the 2GB in A1/B1, A2/B2 & A3/B3 and 8GB in A4/B4 & A5/B5. This will yield 44GB total, a good addition for a server running SBS2011.

That memory configuration should not work. Have you tested this?

Flexible memory configurations are allowed in our 12th generation servers. You will get a message that the configuration is not optimal, but it will work. In previous generations, like the R610, it will give an unsupported configuration error and disable the DIMMs in slots 4,5.:

1-3: 3x2GB DIMMs
4,5: 8GB DIMMs

For this configuration to work you will need two more 8GB DIMMs, so that the two banks have the same number of DIMMs populated. Also, for best results you want to populate larger DIMMs first, so you would put the 8GB DIMMs in 1-3 and the 2GB DIMMs in 4-6.

Thanks

I-Jen · Answer

I just installed the RAM in the Optimized mode and it worked, 2GB in 1,2,3 and 8GB in 4,5.  No memory error.  It reported 44GB total and everything is working much better. Thanks I-Jen

Daniel My · Answer

Thanks for the update! I'll have to check and see if we have added flexible memory configurations via a BIOS update.

4ROB · Answer

Thank You for this ihas /answers ? I had and i Up graded Memore on my Computer,        Have a nice Day   4ROB

I-Jen · Answer

The BIOS version is 3.0.0 for this particular system.

Hiphoptech · Answer

Hello,

I have a R610 and have been able to use 2GB and 4GB in all 6 slots on CPU1 side of the motherboard.

Misconfiguration : Must be paired but 3x2GB DIMM and 3x4GB DIMM WORKED! = 18GB in F2 SETUP

http://tinypic.com/r/2ptdvn7/8

Thanks,

-Hiphoptech

Daniel My · Answer

I thought I read the White Tab slots get the larger module but not sure. Can you clear this up?

It is best practice to install larger modules first. Installing smaller modules first should not cause any errors or issues.

Thanks

PowerEdge Hardware General

Poweredge R610 Mixed Memory

Was this post helpful?