RAM Update in Workstatino Z440 do not work

[Dave_hp]

Edit: This post was intended to continue the other thread with the same title (incuding the misspelling). Unfortunately it was forced into a new thread.  The old thread is here:

https://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/RAM-Update-in-Work...

If a moderator reads this, perhaps you can move this post to the old thread. Thanks.

Very informative posts. However 2 questions remain unanswered:

1. Mixing memory types is not supported. Is "type" just ECC and Registered? Does the RAM have to be all the same as far as the 1Rx8, 2Rx4, etc.?  The specs say nothing about that.

2. It's been suggested that RAM should be balanced between the slots on one side of the CPU and slots on the other side. Is that true? I see some unbalanced configurations labeled "good" in the Quickspec. And what exactly is fair, good or best? What does that mean? Do they not meet the speed spec if the configuration is only "fair"? Do they run cooler if it's "best"? Different latency? Seems bizzarre to throw around such vague terms as "good" and "better". 

Edit: I did see in the HP literature that both 1R and 2R memory will work, but they DON'T say if they can be mixed.

[DGroves]

you can not mix ECC with unbuffered (non ECC) modules

dimm ranks can not be mixed in the same bank, example: if a bank comprises 4 dimm sockets all dimms in that bank must be the same rank so if you have two banks or ram each bank of dim sockets can use different  rank modules 

balanced ram means that each memory bank has the same size/speed/rank modules  some non optional setups are single bank when system supports dual banks of ram or only using 3 banks of ram on a quad channel setup

other non optimal configurations are related to the size of the dimms in each bank, both of these things result in lower memory bandwidth speeds from the fastest possible speed when the optimal configuration(S) are used

[Dave_hp]

DGroves,

Thanks for the reply. I'm not sure I fully understand all of your points.

So is 1Rx4 and 1Rx8 the same rank and therefore can be freely mixed?  

And if I have some 1R and some 2R sticks they can all be used as long as the 1R go into black sockets and 2R into white sockets? Do I have this right?

[DGroves]

go back and carefully reread the paragraph on dimm rank, the answer is plainly posted

yes 1rx4 and 1rx8 is the same rank but different capacity

no, not all black/white sockets are one bank, depending on the chipset a bank can be 2/3 or 4 dimms check your motherboard or workstation manual