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HP Recommended
HP z800
Microsoft Windows 7 (64-bit)

i have a verry irritating issues with my HPz800

problem is if i use more than 2 ram slots on CPU 1 and more than 1 on cpu0 the system freezes up with 2 cpu's installed!

when i install only CPU 0 with all RAM ports filled the system boots up FINE (24gb ECC) IF i fill all slots up on both cpu;s with BOTH cpu's intalled i got ALLOT of ram issues! is there a way to fix this? im realy getting sick of this HP z800, i even swapped the cpu;s with 4 other xeon cpú's spares i have around no luck what so ever i also swapped with another HP z800 mainboard dit solve the problem either, i also shecked the sockets for bend pins with a powerful lamp and magnefied glass


My system specs

HP z800 mainboard REv 1.02 BIOS 3.60 < lates bios! 

2x Intel xeon W5580 3.20ghz

Current installed 3x 4gb ECC HP DDR3 1333mhz

1 Pci-e ssd 160gb IO Fusion drive

1 AMD Radeon R9 380X 4gb

1x 120GB SANDISK SSD ( Windows 7 Ultimate) 

1x 1tb MOE HHD, 2TB MOE HHD,

Crossair 1000 watt modulair PSUDSCF1399.JPG


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1.  From the fist page in BIOS what is your boot block date?


2.  What is the brand of memory?  HP?  Is it all identical?


3.  Is it ECC buffered or ECC unbuffered?

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ram is ECC Memory, Registered

about brand is sheck later today, they all do have a HP sticker on it 

( bought here http://www.ebay.nl/itm/24GB-6x4GB-HP-Z800-DELL-R5500-T5500-T7500-PC3-10600R-DDR3-1333MHz-ECC/2825726... )

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ram info

Hynix  4gb 2Rx4 PC3-106003R-9-10-E1  HMT151R7BFR4C-H9 D7 AA 

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The reason I asked about your boot block date is that the earlier version ran on ECC unbuffered RAM.  Your version 2 should be able to run on both buffered and unbuffered RAM, both ECC.  Of interest, the Z600 and Z800 can run with the ECC buffered sticks I have (like yours), but the Z400 cannot.... all these are version 2 workstations.  The earlier boot block date for the version 1 Z800 is 1/30/09.


What you have as your RAM from the codes should work with both processors, from all I can see.


The workstations can be picky about memory sticks, but it sounds like yours are all identical.


I have a stash of 2GB ECC unbuffered sticks that have the HP part number on them, meant for the ZX00 series of workstations.  If it would help you to know the official part numbers for the 2GB and 4GB ECC unbuffered sticks I can dig that out.  At this point if I was there I'd try using a set of those.

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yea sure what are those offical part numbers?? 

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Here those are..... these will get you the HP images in eBay and from those you can dig around and look for the exact OEM's code, and find identical ones (including HP holographic sticker ones) that way too.


You can't mix buffered with unbuffered.  These all are ECC plus unbuffered.  The first number if more than one is what is on the stick's label.  The ideal is to fill all slots with identical RAM.  Generally you can mix different OEM ones if they have the same HP sticker number.  A few of the 4GB numbers are for identical HP RAM that was for servers.  I've used all of the 1, 2 and 4GB numbers below.


1 GB ECC Unbuffered
500208-562 = 536888-001

2 GB (earlier number) ECC Unbuffered

2GB (later number) ECC Unbuffered
637458-571 = 661621-001 = 536887-001

4GB ECC Unbuffered
500210-071 = 500672-B21
500210-572 = 661524-001 (officially for Z210, work fine in ZX00)


Added tips:  In the version 1 of the Z600 (and I'll assume also the Z800) only ECC unbuffered sticks were supported.  Then came the version 1 to version 2 motherboard roll, and the details (for the Z600) are presented related to memory types and the fact that only the version 2 supported buffered ECC sticks.  Same is true with the Z800 v2.  The PDF link is  HERE:




You have the version 2 Z800, and that PDF is worth reading.


The Z400 (both version 1 and version 2) does not support ECC buffered sticks.... only the ECC unbuffered ones work.  Even with a Z600 version 2 processor (X5672) installed and running perfectly.... I have tried.  No go.


Here's an added screen capture from another HP PDF of the DDR memory QuickSpecs, and this is for the version 2 workstations:


ZX00 ECC all, B & UB option PN.jpg

HP Recommended

thanks for the input im going saterday to a HP workstation specialist shop here in my country to get this sorted out

 btw i found this picture Naamloos.png

is that correctly displayed? CPU 0 slot 1 3 5 CPU 1 slot 6 4 2 ? 

HP Recommended

That illustration is for the Z600 which has a total of 6 memory sockets and which can only use 3 of the 6 if only one processor is present.  Do not use that diagram.  Yours has 12 total sockets, as you know.  The Z800 memory controller and load order is more complex than with the Z600.  Look at the engineer's blog post linked below, the lower diagram, for load order for a dual processor Z800.


One tip..... look closely on the motherboard for the name of each memory socket.  The physical name on the motherboard and in BIOS does not necessarily match the order of plugging them in.  Just physically match the Z800 load order diagram for whether you are testing with 1 or with 2 processors and you'll have that correct.  See pages 161 and 162 of the tech manual below, and note you fill the brown sockets first in both cases.


Here is an early 2009 HP document on Z800 memory loading..... that would be for the version 1 Z800, but the load info likely holds true also for the version 2 Z800.  Look HERE:



There is memory info also in your Z800 technical and service manual.... get the latest one, 504632-004,  HERE:



There also is added Z800 info from a AutoDesk engineer  HERE:



Finally, please let us know what the final issues were.

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thanks for the info i keep it in mind, just gota wait til saterday and see what they wil do with my rig 

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