Mix multiple DIMMs in R640

Question

In a single CPU R640 system. How can I populate the memory if I have these DIMMs.
4 x 16GB (1Rx4)

2 x 16GB (2Rx4)

2 x 16GB (2Rx8)

So, the total would be 128GB.

I tried multiple ways but all ended up seeing only 96GB or 64GB.

Thank you.

Dell-Dheeraj · Answer

Hi @kaynw,   Please refer to the below link for Memory installation guidelines.   https://dell.to/3TogT61

DELL-Marco B · Answer

Unfortunately we only can suggest that guide, you can make some test in order to isolate the issue

kaynw · Answer

Dear Dheeraj, I've read that guide several times, but I still could not mix my DIMMs successfully.

DELL-Shine K · Answer

You can not mix X4 and X8 memory. It is mentioned on the link provided x4 and x8 DRAM based memory modules can be mixed. You can try connecting only below DIMM's 4 x 16GB (1Rx4)  2 x 16GB (2Rx4)

kaynw · Answer

Dear Shine, The guide says 'can be mixed.' Please recheck. Thank you.

DELL-Shine K · Answer

Sorry I overlooked that.

IS all these memory are from Dell? Can you share the Dell part number for these memory modules?

Can you share which all slot you are populating these memory? Can you also check each DIMM one by one and ensure all memory are getting detected standalone.

Do you have latest iDRAC and BIOS installed on the server?

PowerEdge Hardware General

Mix multiple DIMMs in R640

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