Ram upgrade hp elite desk 800 g2 SFF business pc

[Frank1202]

Hi, bought a unit on eBay I’m trying to build for some graphics work. 
everything I read says 800 elite desk SFf can take 64 gb ram. 
it came with 8gb 2133. 4 slots. I bought 4-16gb 2400, put them in no good. 
I figured to fast.  Got 4- 16gb 2133 same thing.  Unit will not start beeps NG 

I go back to 4-8gb, 2133, unit runs fine. Am I being misled?

[TheOldMan]

Yes, that PC can use 64GB of memory.  I would suspect you are getting an incorrect type VS wrong speed.

according to the Cricial site

https://www.crucial.com/compatible-upgrade-for/hp---compaq/hp-elitedesk-800-g2-small-form-factor

They list the compatible memory that is guaranteed to work.

Here is another site listing the type of memory needed.

https://www.memorystock.com/memory/HewlettPackardEliteDesk800G2SFF.html

16GB DDR4 PC4-21300 2666MHz DIMM NON-ECC Unbuffered 288pin 1.2V

[SDH]

To help you we need to know exactly what your business class PC is. It looks to me like there are HP PCs called "HP Elite SFF 800" with a whole bunch of G1 to G9 ones released over the years. Things don't stay the same over such a long run.

We don't want your serial number, I see you have a G2, and there are labels on the outside of your PC from HP that may have added identifying data.

You also could post a good picture of the label face of your original HP memory sticks and also what you tried that failed. There are things like ECC, buffered/registered/ rank and other such details that need to be considered...

EDIT: I found a prior QuickSpecs HP document for this G2 era... it includes all 4 models from mini up to All-in-One so can get confusing. Look at p64 and p126 for added memory info. Note the statements about voltage and UDIMM type needed. I'll try to get you some added specifics. See PDF below with some highlights. I also note it appears your model can run the HP Z Turbo Drive G2 card which may need the latest BIOS to work. This would be a nice upgrade for your boot/applications drive. I'd put it into the second x16 PCIe Gen3 slot that has x4 electrical lanes (which is all a NVMe M.2 stick needs).

[SDH]

Some attached resources below.

Note your specs state 1.2V memory, and they will be ECC unbuffered.

I found you the official Assembly Part Number for your PC's 8GB , below. Try looking for pics on HP's PartSurfer (which can show the AS P/N, but the listings will show the Spares P/N there. Worth a try. The AS P/N is what shows on the label on the right side of official HP memory sticks, so knowing that eases search by eBay. HP has 3 or 4 main part numbers for the same exact part. Two options alphanumerics, the SP and the AS part numbers. What a hassle...

Note the difference between DDR4 and DDR4L. I bet that is a main part of your problem... I think yours demands DDR4L only.

Note that matching memory is tricky and getting the correct ones is key. I'd look also at Micron/Crucial memory buying sites for exactly your HP model. Even they can get it wrong, however. I personally would just use that 8GB part number I show just below, and fill all slots with the same OEM version... all SH hynix for example with the correct HP label on the right hand side and be happy with that.

DDR4-2133 ECC Unbuffered Memory UDIMM for your SFF G2:

4GB 2133 P1N51AA or P1N51AT
8GB 2133 P1N52AA or P1N52AT = 854913-001   (go search eBay for that)
16GB 2133 Y3X96AA or Y3X96AT

You'll see an ad for this on eBay and the stick in the ad allowed me to be sure I had the 8GB Assembly/sticker number correct... this is the packing envelope HP sends out memory in so you know it is right. You'll notice that HP used different OEM vendors for the same AS P/N but I prefer to even get those to match (all Samsung, all Micron, etc.). Supposedly you can mix and match as long as the AS P/N is the same but I don't do that.

[Frank1202]

Hi, and thank you all for the replies.  
‘it’s an HP elite desk 800 g2 sff buisness pc. 
it came with 1 stick, 8gb 2133.

i 1st filled it with 3 more sticks, 8gb, 2133, it runs fine.

i bought 4 sticks, identical, 16gb 2400.  Just beeps and lights flash. Will not turn on.

tried them one by one, same. 
bought 4 more, 16gb, 2133, same, beeps, lights, no turn on.  

guys/girls, I’m in no rush, it works ok at 32gb, I do tax it sometimes. But coming from trying to do my vids and pics with 8gb, and the blue screen of death, this new unit with 32 runs amazing.  So if you need to think a bit, I’m good.  I truly appreciate all of your help, and I mean that.  

[Frank1202]

All, I am using 4 identical sticks of each. The 4, 8gb, 2133 work fine, the 4, 16gb 2133 will not get passed the alarm and red and blue lights.  

[SDH]

Here's a link to your memory:

https://semiconductor.samsung.com/us/dram/module/rdimm/m393a2g40db0-cpb/

Note that fits regarding the need for 1.2V memory. Your new 16GB memory, however, is Registered (aka buffered) as shown in the Specifications on that link... that is what RDIMM means. So it is expected to fail, and it did. That R in "RA0" in your picture above also means Registered. If you want to use 16GB sticks you need to buy what the correct HP memory is... we know it has option codes of Y3X96AA or Y3X96AT, it must be unbuffered, and must run at 1.2V, and it might have Assembly Part Number 854914-001. Go look that up on eBay and maybe give it a try. Then let us know. I'd only get a stick that had the HP sticker on the right-hand side.  The U in "UB1" you'll see in the picture below means unbuffered... these can run faster at 2400 and that is fine... if your processor can run at 2400 also then you'll get benefit from that too. If your processor can only run at up to 2133 the memory will automatically slow down to that.

Good luck with your project.

[DGroves]

dimm "RANK" also comes into play you cannot mix ranks within a memory channel

as such a  R2 and a R4 rank 8GB modules are not compatible with each other even if all other numbers match

https://www.oempcworld.com/support/singlevsdualram.html

ram with a "L" suffix is a low power module (lower voltage 1.35 )

and again can not be mixed with normal ram (1.5v) within a memory channel

what is a memory channel?

https://blog.logicalincrements.com/2019/09/ram-channels-explanation-guide/

[Frank1202]

Hi, just to get this correct (numbers, voltage, buffe, unbuffer) im learning a lot. 
I found the eBay posting with the 16gb stick in red.  I should buy it and try it?

if it works, by 3 more and I should be good?

please let me know. I will purchase today if it’s the right one.  
‘thanks.  

[DGroves]

and yet again even after being told by "SDH" that vague uninformative posts can not be answered you again post such a  request.....................which ebay listing? what are the numbers of the memory module on said listing?