Z400 with Non-ECC memory?

[Tiebreaker]

Can anyone please confirm if the Z400 (2nd gen) can use Non-ECC memory?

The official HP specs only list unbuffered ECC memory as being approved - but I can't find anywhere where it specifically states that Non-ECC memory is NOT approved.

[banhien]

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@Tiebreaker wrote:

Can anyone please confirm if the Z400 (2nd gen) can use Non-ECC memory?

The official HP specs only list unbuffered ECC memory as being approved - but I can't find anywhere where it specifically states that Non-ECC memory is NOT approved.

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Hi,

That's the answer

Regards.

[Tiebreaker]

Thanks for the reply.

The HP whitepaper for Z workstations states that unbuffered DIMMs are supported and then goes on to give the following ..

Unbuffered DIMMs (UDIMM) are high volume DIMMs used in most consumer and entry enterprise applications. As the name implies, none of the signals are buffered. The data and command/address signals go directly into the DRAMs, as shown in the figure below. There are two types of UDIMMs: non-ECC and ECC. Non-ECC UDIMMs can support x8 and x16 DRAMs. ECC UDIMMs can only support x8 DRAMs.

Which kind of implies that unbuffered Non-ECC would be supported in Z workstations.

Or is it supported in some of the Z Series range, but not the Z400?

[Paul_Tikkanen]

Hi, @Tiebreaker :

I believe you will find the exact answer on page 7 at the link below...this document is specific to your model.

ECC, unbuffered memory only...

http://www.hp.com/canada/products/landing/workstations/files/13276_na.pdf

You can also refer to this document which gives you all kinds of info about how to configure the memory in the z400...

http://h20331.www2.hp.com/Hpsub/downloads/HP-Z400-Workstation-memory-configuration-and-optimization....

[Tiebreaker]

OK, thanks.

So it seems pretty clear that Non-ECC memory is not supported, but I'm curious as to what that actually means in practice.

Does it mean ...

1: PC won't boot up. Won't work full stop.

2: PC will work, but with serious issues.

3: PC will work, but with minor issues - ie, just a bit unstable.

Obviously, when I say issues I'm not referring to the lack of error correction that Non-ECC memory will have - that's a given - I'm talking about any other kind of stability issues.

[Paul_Tikkanen]

You're very welcome.

If unsupported memory (non-ECC for example) is installed, upon powering up, the PC will greet you with 5 loud beeps, with the power led flashing red, pause, repeat the 5 beeps, red flashing power LED until the memory issue is resolved.

Your #1 scenario.

I would say that is a pretty major issue. 

[SDH]

A few more details.... as you know there are two versions of the Z400, and the initial Version 1 release had 4 memory slots.  The Version 2 Z400 motherboard, a more recent "stepping" of one of its chipsets, has 6 memory slots and this likely represents the majority of Z400s out there.

The QuickSpecs linked to above gets you to version 4...... and it only deals with the initial Version 1 Z400.  Here is a link to the version 58 of the Z400 QuickSpecs, which mainly deals with your Version 2 workstation (with 6 memory slots):

http://www8.hp.com/h20195/v2/GetPDF.aspx/c04110960.pdf

It is my understanding that Version 2 supports both unbuffered ECC and buffered ECC RAM.... but that HP certification always recommended ECC regardless of buffered or unbuffered. 

In addition here is some good discussion for your memory related questions, from an excellent and helpful HP engineer.  Dan, here, continues to note the need for ECC:

http://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/Z400-Memory-6-slots...

[Tiebreaker]

I've just bought 3 x Z400's from a seller on ebay.

2 of the machines arrived with a mixture of ECC and Non-ECC DIMMs installed - and the 3rd machine had just Non-ECC DIMMs.

I've just booted up the machine with only Non-ECC installed and W7 loaded fine, with no error beeps - while I was browsing with internet explorer there was an error message and explorer closed (although this could be unrelated to the memory of course).

So what's going on here?

It seems that it CAN run on Non-ECC memory, but I'm not sure how.

[SDH]

There is a difference between what HP supports, and what is actually possible for HP workstations.  The HP-supported configurations are generally intended for enterprise level clients needing highest data integrity and workstation reliability.

For example, HP does not support use of Windows 7 or Windows 10 on the xw generation of workstations, but we have been doing that for years with W7Pro64, and now are doing that with W10Pro64.

You can choose to self-validate an unsupported piece of software, OS, or even hardware such as using unbuffered non-ECC memory, and if you succeed to get the stability you're happy with then that is great.

If you master this use of unbuffered non-ECC memory please post back on that!

[Tiebreaker]

Thanks for the explanation.

I don't have any interest in trying to run the Z400 with Non-ECC memory myself, but I've found myself in posession of some machines with the wrong memory installed and needed to understand if it COULD run on it or not.