How to find out what power supply the Z440 have installed

[Jornsl]

Hi. I got an Z440, and got hold of 32GB ECC ram , of LD style, but when booting there is a warning that there is not power to match these units. I have tried to find out which power supply the unit has, but that info has not popped up in any of the docs I've found. Removed most of the memory, only 2 * 16 left, but still the warning.  But the pc seems to work ok. 

Any advice on how to find the power rating, and why this warning pops up?

Best regards Jorn

PS: typo, wrote 16 GB, actual is 32 GB. Editet.

[SDH]

There is no such thing as LD memory.  Maybe you have LR memory? That is not what HP has certified to use in the Z440's QuickSpecs. A quick primer can be found by a google search for "load reduced memory Z440", and read the google AI response, the upper bit of which states:

The HP Z440 workstation can use LRDIMM (Load Reduced DIMM) modules, but there are some considerations. While LRDIMMs are designed for higher capacity and can be used in the Z440, they require more power and can generate more heat than RDIMM (Registered DIMM) modules. Additionally, the Z440's memory controller might not officially support LRDIMMs, potentially leading to boot errors or other compatibility issues. 

Elaboration:

• LRDIMMs vs. RDIMMs:

  LRDIMMs use a single buffer chip to reduce the electrical load on the CPU's memory controller, allowing for larger memory configurations. RDIMMs, on the other hand, have a register chip directly between the CPU and memory, which reduces the distance of parallel transmission. 
• Power Consumption:

  LRDIMMs generally draw more power and generate more heat than RDIMMs

  There have been many posts in the forum here about the problems generated by LRDDR3 and LRDDR4 memory in HP workstations over the years.

  You always can unplug power fully, loosen up the backplane screws, and slip out the power supply just enough to expose the HP label's bottom left corner to see the Spares P/N. Look on eBay also (and below) to see what that looks like and to get an idea where to look to see the max wattage yours is... I'd want the 700W version, not the 525W one. IIRC you don't even need to unplug any cables to see that... just slide it sideways outward and tilt down a bit. Make sure to have unplugged the mains power cable from the wall first.

  If you have a 525W and want the 700W version they are inexpensive recycled via eBay. I've never had one bought that way be bad or go bad later.

  What you want to see...

[SDH]

Jorn,

Just thought of another issue. It still is not clear to us exactly what memory you are running. That is important... for example if you had the HP-certified memory to start with and still in place, and then you added LRDDR4 sticks then you would have created a common cause of failure for your memory to be acting normally. Mixing LR and non-LR memory in the same HP workstation is not good. Sometimes using only LR memory will let things work. However, the error message you're getting is coming from the motherboard/BIOS and it is seeing something it considers improper.

I'd be happy to post exactly what HP has certified as 16GB sticks for these workstations... including pictures if you wish.

[Jornsl]

Hi!. Thanks for both your replyes. I must say I was not aware of the increased power needed by the L-memory.

The units I got hold of are from Planet First: "32GB 4DRx4 PC4-2133P-LD0-10-DC0', also marked 'M386A4G40DM0-CPB'.

Regarding power supply, I did find a clue in a version of the spec found via these pages, where the 750 w do have a video power connector, and that one, I do not have. So the small power.

I got this unit without any memory, so there has been no mix, I tried first to fill all slot, then the requirement for the RAM fan popped up, reduced to two units, and still the power warning. And now I know why.

And if I understand you, these memory units are not suitable for the Z440 in the long run, even if it boots ok, and seems to work.

So info on what units to try to get hold of will be most welcome.

Best ragards Jorn

[SDH]

Jorn,

Thanks for that follow up. The memory you are using is from Samsung, an excellent source HP uses for much of its memory too. That code you provided links to this Samsung site, HERE. I promise to get you the HP16GB stick info shortly... those you got are 32GB sticks. I hope you could return them.

LR stands for Load Reduced and HP workstations have been able to use LR memory (a reduced voltage memory type, but usually they can also run at full voltage). You can imagine that 32GB sticks forced by the HP engineering to run at full voltage would add up to the on-motherboard refusing to accept them.

You may be posting from a Scandinavian country... do you have eBay where you are? I'd recommend looking into getting one of the high wattage power supplies for your Z440 and test with that. If it took away the issue then you may want to run 32GB sticks. More is not always better in this circumstance.

[SDH]

Jorn,

I provided you with the latest Z440 QuickSpecs I have seen as an attachment in a post above. I believe there is no subsequent one so it has the latest HP info. I will attach below a summation PDF of info on what memory HP certified for the Z440, plus an added rare HP PDF on various workstation's memory, v6 (last version), which includes the ZX40 series. The fastest v4 processors the ZX40s can run are 2400 speed. The fastest v3 processors top out at 2133. Note HP never certified 32GB memory for the Z440 (max was 16GB/stick, probably due to cooling issues). They did certify 32GB sticks for the Z640 and Z840 which have higher internal cooling capacity.

Regarding memory... the "rank" for all the HP certified Z440 sticks is single rank... 1Rx4 or 1Rx8. You cannot mix in dual rank memory. Also read the HP note in the PDFs below about needing the special active memory cooling "saddle". For best case cooling usually the motherboard will also demand the front cooling fan option. I install both in all of our high end Z440 builds.

While 2400 speed is the fastest the ZX40 workstations can ever run at you can use faster proper DDR4 and it will down-clock to 2400 automatically in these workstations (assuming you have correct sticks and correct cooling and a v4 2400 processor). For example, HP sends out some 2666 memory as their 2400 product, and they clearly explain that is fine in the QuickSpecs. It actually became less expensive for them to source 2666 memory due to improved yield and volume of production versus the older 2400 memory. The pic below an example of that (and I've also run HP 2933 DDR4 ECC buffered memory from the next generation Z4 G4 fine in a Z440 as an experiment):

2666 sent as 2400, 16GB stick

I believe you'd want 16GB sticks and the part numbers to search for are: 2400 16GB =T9V40AT & AA =809082-591 = 809082-091 = 819411-001. Some HP enterprise memory is exactly the same as HP workstation memory. Other OEMs may use exactly the same as what HP uses. HP reportedly bins their memory to even higher than specs... not sure if they still do that. Mostly HP uses Samsung, Micron, SKHynix memory recently. Clever eBay shopping can get you quite good prices, but it takes knowledge and time. I'd also be happy to provide you the part numbers to search eBay for the Z440 memory cooling "saddle" and the front case cooling fan if you want those.

EDIT: If you find this ad on US eBay I think you'll be very happy. Note it is the HPE server memory; same as ZX40:

See attached resources, and please get us an update, if possible, to help others: