Xeon D 1500 and 2100 RDIMM and LRDIMM compatibility

sfbayzfs

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May 6, 2015
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Hi all,

When the Xeon D 1500 series came out, the only way to max a board out with 128GB was with 4x 32GB DDR4 ECC Reg.

Nowadays, it looks like you can get 64GB DDR4 both as RDIMM and as LRDIMM, plus 128GB as LRDIMM only. I do see people selling 128GB "RDIMM" memory, but those which I have looked up are all actually LRDIMM parts. By the specs on the Xeon D 2100 series family boards with 4 RAM slots (256GB max RDIMM, 512GB max LRDIMM), 64GB DDR4 should at least be available as RDIMM, but can anyone confirm seeing 64GB DDR4 both as LRDIMM and as RDIMM in the wild, or are they all RDIMM or all LRDIMM?

I suspect the Xeon D 1500 series cannot handle LRDIMMs at all, but has anyone tried 64GB RDIMMs in a Xeon D 1500 series board? Even if it is locked at 128GB max (Intel is often very strict on max RAM in their memory controllers) it would be nice to be able to max a Xeon D 1500 board with 2x 64GB RDIMMs instead of 4x 32GB if possible.

Cheers!
 

Evan

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Jan 6, 2016
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First 64gb dimms were LRDIMM, more recently you can also get just straight RDIMM in 64gb size.
Same with 32gb dimm you can get in both LR and RDIMM.

I don’t have any 64gb rdimm to try but I assume they won’t work in d-1500 boards. 4 x 32gb rdimm is kind of the cost effective (if you could call it that) and practical limit.
 

sfbayzfs

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May 6, 2015
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I didn't expect it to work, but for the record, I tried a 128GB LRDIMM which works great in my Xeon D 2100 series board in my Xeon D 1500 series board, and it hangs during POST before getting very far a all.

If anyone has regular RDIMM 64GB they can try in a Xeon D 1500 board, please do so and report your results!
 

kyle steinkamp

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Feb 8, 2018
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My 24/7 ESXi server has the D1508 and is using 32GB LRDIMMs.
The board I have is the supermicro X10SDV-2C-TP8F with 2 sticks of Samsung M386A4K40BB0-CRC for 64GB in all. Its not more than 128GB but it is running LRDIMMS on the D1500
 

sfbayzfs

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May 6, 2015
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Interesting, that is a 2Rx4 part, so now we just need to test if 64GB LRDIMMs work in xeon d 1500 series boards or not! (There is probably still the 128GB max ram limit if they do work)

The original 128gb LRDIMM I tested in my 1500 board was 8R, but based on your test, I will try a 128GB 4R LRDIMM in a 1500 series board to see if that works!
 

WenleZ

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Aug 9, 2016
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This is an old thread, but was anyone else able to confirm if LRDIMM is working on the Xeon D-1500 series, specially with Supermicro's X10SDV series boards? I had a X10SDV with Intel Xeon D-1541, and it did not work with 32GB LRDIMM.
 

Evan

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Jan 6, 2016
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No the D-1500 does not support LRDIMM only RDIMM (and udimm but that’s not likely people want to use as rdimm is cheaper)
 

kyle steinkamp

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Feb 8, 2018
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I have a correction to my post from last year. I pulled my server apart this weekend for cleaning and found I do not have LRDIMMs. I have 2 sticks of Samsung M393A4K40BB1-CRC. I do have some of the sticks I thought I used before and tried them and the box does not boot.