Dell Precision 7820 Memory Configuration

When you have dual 6138, memory should be on both, motherboard and riser board.  Review the memory matrix D96R and installing 3 DIMM on each board  https://www.dell.com/support/manuals/en-us/oth-xlt7820/precision_7820_om_pub/memory-configuration?guid=guid-ce1561c8-88a9-45e3-bc3b-762cbb37e073&lang=en-us

@Chino de Oro​ Highlighted the once I'm referencing from the picture.

So if I'm understanding this correctly. Then the dimms should be configured as follows. All reference is done from pictures of main boards with power connectors in upper left corner.

Main mother board:
------ Dimm 2 cpu 0
------
------
------
------ Dimm 3 cpu 0
------ Dimm 1 cpu 0

Riser/2nd cpu board:
------ Dimm 2 cpu 1
------ Dimm 4 cpu 1
------
------
------
------ Dimm 1cpu 1

@Chino de Oro​

Top picture is main board 2nd picture is riser board. I’m pretty sure this is the same order that we are both saying. 

If this is the correct order then it didn’t make a difference. CPU z is still saying the same thing for timings and saying triple channel. 

All the information from my posts are to answer your questions:

Should all 6 be on the bottom main board with just one cpu or should it be split? 

I feel like from what I could understand that with me having 6 16gb sticks they should all be on the bottom board with. But I honestly don't know that's why I'm reaching out for some help.

@Chino de Oro​

​I think there was a misunderstanding. I added the pictures of my motherboard just to confirm that we were both saying the same things. About where the placement of the sticks were suppose to be. So I put them in that order and sent a pic for confirmation. 

Your comments helped a lot. (Sent from mobile and it was glitching so I deleted and reposted this)

Yes, I can confirm that your pictures have shown the correct memory configurations as the memory matrix we have discussed about.

The system supports six channel memory and you have dual Xeon gold 6138, which is Skylake, hence the memory runs at 2666 MHz.

I have set up an exact system with the same CPU.  A Quadro RTX 6000 with dual NVMe SSD on upper flexbay, dual Exos HDD in lower flexbay, and four enterprise NVMe SSD (110mm) on PCIe x16.  Therefore, am very familiar with this system.

@Chino de Oro​ since the memory config is correct. Even though it shows 2666 in task manager. It shows the 1330 for timing in cpu z. Am I just misunderstanding? is there a way to confirm that I’m actually running at 2666?

The timing is for single data rate when displayed in utility such as CPU-Z.  With DDR (double data rate), it is 2666 MHz.

Task Manager, Performance tab, Memory should display the correct memory speed.

@Chino de Oro​ thank you very much for your help. I just didn’t understand. I thought I was still doing something wrong. I didn’t realize it was doubled like that. 

Glad to help out.