I'm upgrading a PowerEdge T310 to its maximum allowed memory of 32GB. The compatibility information in the manual lists the following:

Your system supports DDR3 registered DIMMs (RDIMMs) or unbuffered ECC DIMMs (UDIMMs). Single and dual-rank DIMMs can be 1067- or 1333-MHz, and quad-rank DIMMs can be 800- or 1067-MHz. Your system supports single-channel mode and dual-channel mode. The system contains a total of six memory sockets. UDIMM supports single-rank and dual-rank DIMMs. Only RDIMM supports quad-rank DIMMs. The maximum memory that is supported on your system varies according to the types and sizes of memory modules being used:

• Single-rank and dual-rank RDIMMs of sizes 2-GB, 4-GB and 8-GB are supported for a total of up to 24 GB.

• Quad-rank RDIMMs are supported for a total of up to 32 GB.

• 1-GB and 2-GB UDIMMs are supported for a total of up to 8 GB.

The system is currently fitted with 4x PC3L-10600 (unbuffered, non-ECC) modules of 4GB each.

If I read this information correctly, I should be able to upgrade this with 4x PC3L-10600R modules of 8GB each, maxing out the available memory and giving me the benefits of ECC.

The memory new I purchased, reading directly from the label on the sticks, is "8GB 2RX4 PC3L-10600R-9-10-E1" (Hynix HMT31GR7BFR4A)

After installing the new memory, the system will not POST, and the front LEDs have diagnostic lights 1 and 4 lit. I installed the new sticks into the exact same slots (channels A and B, slots 1 and 2) as the previous memory.

Returning the original memory leads to a normal boot.

I need to know if I've somehow purchased the wrong memory by misreading the information, or if my new memory is faulty somehow (I'd expect a later error, rather than an outright boot failure in this case).

  • What does the manual say that lights 1 and 4 signify? – joeqwerty Feb 10 '19 at 21:26
  • Just in case you missed it, also note the data width requirements mentioned in the technical guidebook. I've updated my answer to point that out. – Bob Feb 11 '19 at 7:31

Take a look at the technical data sheet for your memory.

Specifically, the HMT31GR7BFR4A you have is dual-rank, not quad-rank.

Your system probably does not support dual-ranked 8 GB for 32 GB total (assuming your manual is correct, as it's a bit different from this technical guidebook). You'd want HMT31GR7BFR8A, which is quad-ranked 8 GB.

Also note from the technical guidebook:

T310 supports x8 (data width) and does not support x4 and x16 DRAM on RDIMM

You're attempting to install 2Rx4. HMT31GR7BFR8A is 4Rx8 so I'd expect it to satisfy these requirements.

Of course, other manufacturers (e.g. Samsung) also make RDIMMs in that configuration.


Diagnostic lights 1 and 4 means system board failure. Either you have the incorrect RAM, A bad ram stick or a bad system board. I looked at the firmware updates and none address an issue with ram.

  • That was confusing me too, but I find it very unlikely that the system board has a problem considering it runs completely normally with the memory already in there. – Mikey T.K. Feb 11 '19 at 7:03

The manual excerpt you provided states Single-rank and dual-rank RDIMMs of sizes 2-GB, 4-GB and 8-GB are supported for a total of up to 24 GB.

Your modules are 8GB dual-rank RDIMMS, and exceed the 24GB maximum as per the manual. Try with 3 modules.

  • It won't even boot with one or two sticks installed – Mikey T.K. Feb 11 '19 at 7:14

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