PowerEdge R910 4x16GB issue

Draganik,

When adding the dimms to the server you need to remember these:

• All populated memory risers must have identical configurations.
• The memory configuration for each processor must be identical for optimal performance.
• Memory modules of different sizes can be mixed (for example, 2 GB and 4 GB), but all populated channels must have identical configurations. 

What you can try is placing 16gb dimms in slots A1, A3 B1, and B3. Then place the 4gb dimms in slots A2, A4, B2, and B4

Let me know if that allows it to coot.

Hi,

As mentioned before, my R910 was with 4x4GB and the idea was to replace all 4GB DIMMs with 16GB DIMMs. Instead of 4x4GB new configuration should be 4x16GB but it didn’t work. All 16GB DIMMs were installed in the same slots as 4GB DIMMs. Message was:

NON CONFIGURABLE MEMORY DETECTED

SYSTEM HALTED

It’s very strange for me. The question is: Is 4x16GB memory supported configuration?

THANKS

What slots are populated? How many processors installed?

Hi Chris,

Our R910 is with 2CPUs and two risers.

According to DELL documentation risers are on A and C positions

Present configuration is:

• two CPUs
• two risers, A and C
• 4GB memory modules are one risers A and C, 
• all modules are 4GB
• total amount is 4x4GB

this is from DCSE manual:

• All systems will include either 1 or 2 Memory Risers per CPU socket
• Supported configuration is a minimum of two DIMMs (one locked-step pair) in each riser
• Memory must be populated beginning with DIMM Slots {1,2}

In my situation, mixing of 4GB and 16GB is not request.

We would like to replace all 4GB module with 16GB modules but it doesn't work. New 16GB modules were installed on the same possition as 4GB modules.

Once again, is 4x16GB supported configuration?

Best regards,

Dragan

With the 16gb dimms the Optimal configuration would be 512GB across 2 risers. You can see the configuration on page 96 here -  http://ftp.dell.com/Manuals/all-products/esuprt_ser_stor_net/esuprt_poweredge/poweredge-r910_Owner%27s%20Manual_en-us.pdf

This actually sounds like it may be an issue with incompatibility between the processors and dimms. What model processors and 16gb dimms are you using in the server? Does it happen to be a Nehalem processor? If so then let me know the specs for the dimms you purchased, I will verify their compatibility.

Processor is E7540 2.00GHZ

Memory modules:

16GB Module - DDR3L 1333MHz

Part Number: KTD-PE313LV/16G  

Specs: DDR3L, 1333MHz, ECC, CL9, 2R, X4, 1.35V, Registered, DIMM, 240-pin

Dragank,

The system does support 16gb dimms. Their part number is A6994473. I hope this helps.

hi Chris,

We've also got a R910 with a slightly different processor - Xeon X7500.

Currently we've maxed out the ram to the 2 cpus with 8gb dimms in all 32 slots. It is possible to use 16gb dimms of any type for these processors or does the architecture not support it?

many thanks,

Sam

Would the E7-4820 Processor also support the A6994473?

Use quad rank memory

Hi Chris, this comes in a bit late, but hope it will be picked up. I know the details are a bit different, but this is the closest issue that I could find, so hope to pick up the thread here.

I have  a R810, that started out at Bios 1.2.0. It contained 16 x 16GB RAM (SNPMGY5TC/16G) which booted fine. The system has 4 x E7450 CPUs installed. The memory is/was installed in the white tab slots, x1 - x2 - x3 - x4. The other slots were populated by plastic blanks to keep proper airflow.. 

When upgrading this system to the latest available Bios, 2.9.0, the system showed a brief Dell logo, before stopping on a "System Halted" message.

I tried replacing the memory with 16 x 8GB RAM, and the system booted again (with suboptimal RAM config warning, but functioning fine).

Troubleshooting further, I found the 2.1.0 Bios to be the one to break compatibility with the 16GB RAM sticks. In the release notes, that Bios does indicate a significant amount of microcode updates.

When looking into the SNPMGY5TC/16G RAM stick details, they mention the need for an E7 CPU to run. I believe the E7450 should be compatible (as it did indeed work on older Bios), but  I have also recently upgraded to 4 x E7 4870 CPUs, repeated the troubleshooting steps above, but with same results.

So, to summarize: 

SNPMGY5TC/16G should be compatible with R810 (4 x E7 4870 CPU), is positioned in white tab memory (x1 - x4) slots according to the config in owner manual:

CPU :2/4

Total mem: 256

DIMM size: 16

Number of DIMMs:  16

The system does show VGA screen, but goes directly to "System Halted" message.

A direct replacement back to  8GB sticks (1:1, same slots) brings the system back to life. The 16GB sticks worked fine in pre-2.1.0 Bios (with any CPU). Memory tests running on Bios 1.2.0 indicate no error on 16GB sticks. I have tested the sticks with 8 installed at a time (instead of 16), and then replacing them with the other 8. Both give same "System Halt" result.

It seems clear that the problem lies in compatibility after the microcode in Bios 2.1.0 and later.  

Do you have any more information you could provide on this? Any suggested further tests I could do?

With my R910, I had to populate a minimum of TWO DIMMs per memory cartridge/riser. So the minimum number of DIMMs needed to get the thing to boot was:

2 DIMMs in every other cartridge (empty cartridges are more or less ignored), which means 2 DIMMs per CPU. The R910 has 4 CPUs, so I had to populate every other cartridge (each CPU gets 2 cartridges) with 2 DIMMs for a total of 8 DIMMs. The pair of DIMMs should go on the top two slots (Slots 1 and 2) of each populated cartridge.

I think you may need to populate DIMMs two at a time. So for example, you may get the error message if you have 3 DIMMs in each cartridge. I would start with the "minimum" (2 DIMMs per cartridge or 0 DIMMs, at least 2 DIMMs per CPU) and ensure it boots with that.

What's more, it looks like the two DIMMs you populate each riser with must be the same. I was unable to POST with every other riser populated with an 8GB and a 16GB DIMM in Slots 1 and 2. If this is correct, then you will need a minimum of 8 of the same exact DIMM (maybe capacity just needs to be the same but I suspect it's more than that) for an R910 with 4 CPUs to even boot.

dont know why but nobody said about it.....here i am able to test the exact same r910 with the same procs(e5-4870) but changing only the generation of memory risers(yes there are two) gen 1 has nothing writen on it but gen 2 has a " II " on it like the front of 2950 and some m610 (to represent their generation)

btw here are some tests:

worked memory riser gen1: 4gb 10600 2rx4 / 8gb 10600 2rx4

worked memory riser gen2 ( II all memory types except i didnt tryed 4gb

did not work on gen1 riser: 8gb 10600 pc3L (low voltage) but worked on gen2 riser / 16gb pc3L 12800 / 16gb 10600 pc3L

I dont have now here 16gb not Low voltage to try but seems to me that gen 1 do not acepts Low voltage memory