R715 Memory Configuration Not Optimal - After Upgrade

Hello everyone,

I have been attempting to find a solution to a memory configuration issue by reading the Hardware Owners Manual, and Technical Guide but am unable to determine what I am doing incorrectly.

I currently have a Dell PowerEdge R715 with 64GB of memory in the following configuration:

Qty 8 HMT31GR7BFR4A-H9 8GB 2Rx4 PC3L 10600R

A1 Memory module slot A1 (white release lever) 8GB 2Rx4 PC3L 10600R

A5 Memory module slot A5

A2 Memory module slot A2 (white release lever) 8GB 2Rx4 PC3L 10600R

A6 Memory module slot A6

A3 Memory module slot A3 (white release lever) 8GB 2Rx4 PC3L 10600R

A7 Memory module slot A7

A4 Memory module slot A4 (white release lever) 8GB 2Rx4 PC3L 10600R

A8 Memory module slot A8

B1 Memory module slot B1 (white release lever) 8GB 2Rx4 PC3L 10600R

B5 Memory module slot B5

B2 Memory module slot B2 (white release lever) 8GB 2Rx4 PC3L 10600R

B6 Memory module slot B6

B3 Memory module slot B3 (white release lever) 8GB 2Rx4 PC3L 10600R

B7 Memory module slot B7

B4 Memory module slot B4 (white release lever) 8GB 2Rx4 PC3L 10600R
B8 Memory module slot B8

 

When I attempted to add an additional 64 GB of memory (by adding Qty. 4 SNP20D6FC/16G
16GB 2Rx4 PC3L 12800R) in the BELOW configuration I received the “Memory not optimal” error at bootup. I was still able to boot the server, but had to acknowledge the error to proceed.

 

A1 Memory module slot A1 (white release lever) 8GB 2Rx4 PC3L 10600R

A5 Memory module slot A5 16GB 2Rx4 PC3L 12800R

A2 Memory module slot A2 (white release lever) 8GB 2Rx4 PC3L 10600R

A6 Memory module slot A6 16GB 2Rx4 PC3L 12800R

A3 Memory module slot A3 (white release lever) 8GB 2Rx4 PC3L 10600R

A7 Memory module slot A7

A4 Memory module slot A4 (white release lever) 8GB 2Rx4 PC3L 10600R

A8 Memory module slot A8

B1 Memory module slot B1 (white release lever) 8GB 2Rx4 PC3L 10600R

B5 Memory module slot B5 16GB 2Rx4 PC3L 12800R

B2 Memory module slot B2 (white release lever) 8GB 2Rx4 PC3L 10600R

B6 Memory module slot B6 16GB 2Rx4 PC3L 12800R

B3 Memory module slot B3 (white release lever) 8GB 2Rx4 PC3L 10600R

B7 Memory module slot B7

B4 Memory module slot B4 (white release lever) 8GB 2Rx4 PC3L 10600R
B8 Memory module slot B8

 

 

 

 

 

 

I read in the Owners Manual that the highest ranked DIMMS should be installed first. Although the memory is all quad ranked, I decided to place the 16GB DIMMS “First” as follows:

 

 

A1 Memory module slot A1 (white release lever) 16GB 2Rx4 PC3L 12800R

A5 Memory module slot A5 8GB 2Rx4 PC3L 10600R

A2 Memory module slot A2 (white release lever) 16GB 2Rx4 PC3L 12800R

A6 Memory module slot A6 8GB 2Rx4 PC3L 10600R

A3 Memory module slot A3 (white release lever)

A7 Memory module slot A7 8GB 2Rx4 PC3L 10600R

A4 Memory module slot A4 (white release lever)

A8 Memory module slot A8 8GB 2Rx4 PC3L 10600R

B1 Memory module slot B1 (white release lever) 16GB 2Rx4 PC3L 12800R

B5 Memory module slot B5 8GB 2Rx4 PC3L 10600R

B2 Memory module slot B2 (white release lever) 16GB 2Rx4 PC3L 12800R

B6 Memory module slot B6 8GB 2Rx4 PC3L 10600R

B3 Memory module slot B3 (white release lever)

B7 Memory module slot B7 8GB 2Rx4 PC3L 10600R

B4 Memory module slot B4 (white release lever)
B8 Memory module slot B8 8GB 2Rx4 PC3L 10600R

I had no success with this method. My thoughts are that the server may want all 8 slots filled.

Any ideas? My VAR is not giving me any assistance.