Did you have 2 processor or 4 processor on the server? What memory did you had on the system before installing these new memory? Did you have latest BIOS FW installed on the server? If not can you update latest BIOS and check the behavior? Can you also share the part number of the DIMM modules? Are these Dell branded?

Hi.

I have nearly the same problem. Now my  R910 have 4GB modules, total of 32GB (2Rx4 PC3-10600R-09-10-E1-P1 (M393B51570FH0-CH9Q5 https://www.itcreations.com/product/25127 )), so every second riser have 2 modules. That's fine, but now I want to put four 16GB module (2Rx4 PC3-12800R-11-13-E2 (MT36JSF2G72PZ-1G6E1FF https://www.itcreations.com/product/81759 )). If I leave the system as is and put the modules to the empty riser the system say "Unsupported Buffer and Memory Configuration". If I remove every old riser and put just the new modules, it say "Invalid Memory Configuration  Halting System.".

I updated the bios, but no still luck :( . What is the problem?

Thanks

Hello,

those memory banks are not supported in the system because they are 1600 Mhz.

Your system supports DDR3 registered DIMMs (RDIMMs). Single-, dual-, 
and quad-rank DIMMs can be 1067 MHz or 1333 MHz. 

Page 91

Dell PowerEdge R910 Hardware Owner’s Manual

Thanks

@DELL-Marco B​ 

Ohh, I see :( . Of course I read the manual, but I thought it can work, just downclock itself... Some page says it is compatible, for example here: https://getprice.pl/en/12800r-1600mhz/537-mt36jsf2g72pz-1g6e1ff-micron-16gb-2rx4-pc3-12800r.html

Thanks for the answer!