Is Z400 RAM Compatible With newer Z420 Workstation?

[Wunderbar]

Hi I have Z420 Workstation, I'd like to replace RAM modules and I wonder if previous series Z400 RAM can be useful for my system, or should I get new ones? Modules are HP standard DDR3 unbuffered ECC memory PC3-10600E. Does same apply to Z600 and Z620? Thanks!

[SDH · Accepted solution]

You may know that there are two versions of the Z400 and two of the Z420.  You can identify what you have in your Z420 by looking in BIOS under the first tab for your boot block date.  You may also know that HP officially certifies specific ECC unbuffered memory sticks for the Z400 and faster ones for the Z420 version 1 workstation, and even faster ones for the Z420 version 2 workstation.  They do not certifiy ECC buffered for any of the Z400 or Z420 versions. Those ECC buffered sticks can be used in the Z600 version 2 and both versions of the Z620.  With all these complexities it is good to know that there are some significant cross-compatibilities.

Different speeds for the HP ECC unbuffered DDR3 memory, simplified:

1333Mhz = PC3-10600E = for the Z400      (the E means it is ECC, and I wish they'd put in UB for unbuffered)

1600MHz = PC3-12800E = for the version 1 Z420

1866MHz = PC3-14900E = for the version 2 Z420

The processor being used can slow down the memory but cannot speed it up over its top rated speed.  Thus, using the 1866 memory with a processor that is rated to 1600 or 1333 will result in that processor running at the slower speeds noted.

I have personally run the 1333 ECC unbuffered memory from a Z400 version 2 in a Z420 version 1.  And, 1333 ECC buffered memory from a Z600 version 2 in a Z620 version 1.  And, 1333 ECC buffered memory from a Z600 version 2 in a Z620 version 2 running a 1866 E5-1650 v2 processor.  There will be no harm to experiment.  I don't run HP ECC buffered in the Z400 because I tried and failed.  I have not yet tried running that in the Z420 version 2.

A key thing.... there is a significant speed benefit from filling all your memory slots with identical RAM, so if you have 6 HP sticks from your Z400 that are 1333 ECC unbuffered just get two more for your 8 total slots in your Z420.  For me with Z420 version 2 workstations I only run the v2 processors that are rated to 1866MHz, and load all 8 slots with identical 1866 HP ECC unbuffered memory.  Running 1333 for you at this point would be fine, and that might free up some funds for a fast v2 processor if you happen to have a version 2 Z420. 

[Wunderbar]

Thanks SDH!

Your info was really helpfull 🙂 unfortunately I can't start the machine and go to BIOS, as I'm waiting for some parts to arrive. This is my motherboard barcode and part number. Can u tell which version it is by looking at photo? 

[SDH]

You don't mention what processor you currently have.  You may be building up a Z420 from scratch.  Do you have a version 1 processor?  You should be aiming for a v2 processor because that is a version 2 motherboard, and also can run the 1866 memory as long as it has a HP approved 1866 processor.  However, you want to use your slower memory but that can be upgraded later.

The version 1 motherboards can only run the HP approved v1 processors, but the version 2 motherboards can run the v1 or v2 HP approved processors.  So, maybe buy a v2 processor now and run it with your slower memory until you find good deals over time on used HP eBay 1866 ECC unbuffered memory.  Look at the cost/GB for 2GB vs 4GB sticks to get an idea on that... there are specific part numbers you'll find which include option part numbers, spares part numbers, and assembly part numbers, all for the same sticks.  The easiest to find is the assembly part number on the stick, on the HP label.  There are multiple vendors HP uses for memory, with the same AS P/N, but I like to use the same vendor for all sticks.  Micron, for example, but SK Hynix is common too. Less common to see Samsung it seems.  Once you know the vendor's part number from their label you can search for that too.

Regarding your pic.... the two entries to the left have to do with what OS that motherboard can be encoded for in its firmware... Linux vs Windows.  This has to do with cash/licensing so it will be one or the other, not both. The "W8" there means it can be W8Pro64 and W7Pro64 licensed.  The "encoded" has to do with what also is called  to "brand" or "tattoo" the motherboard.  Same thing.... specific codes are entered and the motherboard will then be able to accept the HP OEM COA Recovery/Install media for what it is branded to accept.  Those codes are on the labels on the case, and should also tell you if your case is licensed for Linux or Windows.  Thus, if you bought a used motherboard you won't know until you try the HP OEM COA media during an install if it is branded for Linux or Windows.  If it is a new virgin motherboard you'll have to learn how to brand it properly, which is a one time event that cannot be reversed, and more than a bit of a hassle (but can be done).  Old info on HP branding has almost nothing to do with the current process so don't read old stuff on that.  Lets just assume it was used and is already branded for Windows 7/8.

[Wunderbar]

SDH thanks a lot for your help!

The strange thing is that I have this motherboard with preinstalled E5-1607 v1 and a heatsink. I'm trying to build a system with it if I can 🙂 The tricky thing is that I dont have any other components besides Samsung 850 Evo SSD, PSU, motherboard and CPU. RAM modules should arrive in couple days. I'm not even sure if I can start the machine without other components. The USB and power cable connector pinout looks really different from other motherboards I've seen so far 🙂 Can I assemble it in a standard case? or is HP case a must with it's cables, coolers and stuff?