Memory slot problem

[hopalı]

Slot 3 of Processor 0 of my HP Z840 computer does not work (red light turns on 5 times when I insert memory into this slot). Is there any problem if a slot is empty?

[DGroves]

to use both memory banks a second cpu must be inserted if only one cpu is installed only the memory banks next to it are active

memory slot load order is printed on the side cover, each mem bank (two dimm slots) must contain the same dimms

you can mix dimm size between mem banks however ie- bank 1 uses two 8gb sticks bank 2 uses two 16 gb dimms

however bank one (and two) cannot have a 8gb and a16gb dimms installed

the installed power supply (850 or 1200 watt) will also determine what wattage cpu's can be installed

also several pci-e slots are not activated unless the sec cpu is installed, these things are covered in the user manual so you will most likely want to read it before posting further

[hopalı]

Thanks for your response. I have two E5 2590 v4 processors. Memories are loaded as seen in the picture. 8x16GB. The computer is running 128 GB Memories. I bought 4 64Gb memories. I don't know exactly where to upload it. Because slots 7 and 8 of the RAM slots belonging to CPU 0 don't work.

[hopalı]

Thanks for your response. I have two E5 2590 v4 processors. Memories are loaded as seen in the picture. 8x16GB. The computer is running 128 GB Memories. I bought 4 64Gb memories. I don't know exactly where to upload it. Because slots 7 and 8 of the RAM slots belonging to CPU 0 don't work.

[DGroves]

•

Load the memory modules in order of size, starting with the largest module and finishing with

the smallest module.

•

Each channel includes two DIMM sockets; black and white connector pairs represent a channel.

For a single processor configuration, the DIMMs should be loaded first in the black sockets and

then in the white sockets. The DIMMs should be loaded starting with the DIMM furthest from the

CPU, with the first DIMM loaded in the bottom most socket and alternating sides of the CPU.

•

For a dual processor configuration,  alternate between the 2 processors

see page 24 on the link below

https://manualzz.com/doc/o/rxdmf/hp-z840-workstation-memory-configurations-and-optimization

so on cpu "0"  the bottom 4 dimm slots

fill the bottom most  dimm slot, now skip a slot and fill the "3rd" slot

now the 4 slots on the top of cpu "0" , again bottom to top 

now do the same load order on the cpu 1 dimm slots

Example: dual cpu's both cpu dimm slots have the same load order

x no Dimm

Dimm

x no Dimm

Dimm

    CPU 

x no dimm

Dimm

x no dimm

Dimm

if error try swapping dimms between sockets, does error dimm number error change in bios message?

if so bad ram if not check for bad pins in dimm socket and clean dimm and dimm socket socket w/99% alcohol

if no change, swap cpu's between sockets as the memory controllers are inside the cpu's does error location change? if so bad cpu if not possible bad cpu socket check for bent pins,

[hopalı]

Thanks for the information you provided. But the slots marked in the image I sent do not work (slot 3 and 11). If there is an order like the one in the picture, will there be a problem? In which slot can I load the last remaining memor?

[DGroves]

please state the number (total) of dimms you have and their sizes

from your last picture you are not loading the ram in the correct sequence

[hopalı]

4x64 GB

8X16GB

The memory slots to be loaded into 3 and 11 marked in yellow are not working.

thanks a lot

[DGroves · Accepted solution]

improper memory, you will need to either add 4 more 64gb dimms for a total of 8

or remove four 16gb dimms (installing only 4)

each cpu has 4 memory controllers and a controller connects to two dimm slots, one black and one white

each black/white dimm pair must have the same capacity dimms to work correctly

the correct load order of your existing setup using 64 and 16 gb is

 largest dimms first (on slots furthest from cpu)

 then small capacity dimms

(load order on cpu 0 is then duplicated on cpu 1)

so for the 64gb dimms cpu 0 uses slots 1 and 8, this configuration is then duplicated on cpu 1

this setup places a single dimm in two of the four available memory banks causing the memory speed to be halved not ideal but it is a approved configuration allowing 4 more 64gb dimms to be added later for dual channel operation of each controller the next slot towards the cpu must also be a 64gb dimm, since you do not have any more this slot is skipped and

we now install 16gb modules in pairs in the remaining two memory controllers blk/white dimm slots

8-64gb  blk

7-empty white

6-16gb blk

5-16gb  white

CPU 0 (duplicated on cpu 1 dimm slots)

4-16gb  white

3-16-gb blk

2-empty white

1-64gb  blk

[hopalı]

Thank you very much for your interest and help.
I will share the result. Kind regards