Z600 registered memory support on B3 stepping. Why is it not supported?

[roadrunner321]

Hi,

I bought a Z600 motherboard off of eBay, and I didn't know about the bootblock at that time. So evidently I got the older, B3 revision:

AS#460840-002, with bootblock date 01/30/09.

After doing a lot of research I think I know pretty much all there is to know about it, so I decided to try and update the bootblock. I bought spare flash memory chips, Atmel AT26DF161 and a Raspberry Pi 3 B+ and I will try to write a fresh BIOS on it.

But still one thing puzzles me, I cannot understand why will registered memory not work on the older bootblock versions. The main reason for the confusion is that on the Intel Xeon 5500 and 5600 CPus the memory controller is on the CPU itself. Given that the difference between Z600 v1 and v2 is mainly the chipset, one being stepping B3 the other C2, what is the connection with the support for registered memory? Is it really the chipset, B3 not supporting registered ECC memory?

I have already asked this question on the Intel support community here:

https://forums.intel.com/s/question/0D70P000006Egrm/intel-5520-tylersburg-ecc-registered-memory-supp...

No ueful response, so I thought I should ask here too. Can anyone give a technical response and shed some light?

I guess the main reason I'm asking this is to understand if upgrading the bootblock will do it, but otherwise I would just be happy to learn about the architecture of the system and where is the limitation.

Thank you!

[DGroves]

i recomend not trying to override the bootblock with the v2 bios code as the chipset does indeed have numerous changes from the  B3 to the C2 revision to have/enable  ECC support, the CPU, Ram, and chipset must all have support for ECC, and the B3 revision appears to lack this support

you will be better served in my opinion  to simply aquire a v2 motherboard

[SDH]

I agree fully with DGroves.... don't know how much you have spent on your gear but a version 2 Z600 motherboard is quite cheap these days and takes me only about 1/2 hour to swap in.  I'm sure we both know this is not welcome news to you.....

Spend some time looking at the eBay motherboards and getting a sense of which are the most recent from the white bar code SP and AS numbers and the Rev alphanumeric.  Look up Z600 spare parts and the v1 vs v2 part numbers for the motherboards start to make sense.

[roadrunner321]

The thing is I've already bought this motherboard and got dissapointed by all the limitations (including the max 95W TDP support), so eventually I got a SuperMicro X8DA3 and built another PC instead.

But given that I have this mobo laying around doing nothing, I decided to go crazy with it, I really wouldn't care too much if it broke down, then I might replace the motherboard with a newer revision. I found a temporary use for the Z600, for running MacOS, but otherwise I'm not very fond of it anymore.

Can you point me to the exact piece of information around B3 revision lacking support for ECC registered memory? I looked at the datasheet [1], looked for stepping, B3, C2 and the likes. I have a degree in Computer Science and I am familiar with HW design in general but I don't know enough about ECC registered memory support or how this interconnects with the memory controller in the CPU.

Edit: Perhaps it's worth mentioning I've only got the motherboard, I made a custom build around it, with a couple of Noctua coolers, a Cooler Master HAF-X and an FSP Hydro G PSU. I can reuse all of the aforementioned components, but right now I would rather put the motherboard to some good use. Besides, I've got too many PCs laying around.

[1] https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/5520-5500-chipset-ioh-datash...

[SDH]

"Besides, I've got too many PCs laying around..."  my wife would agree with you, about me.

I just don't know about the differences because I figured out early that the version 2 of the Z400/Z600 or the Z420/Z620 was the only way to go.  The prices on the version 2 Z420 have really come down.  The thing that many don't know is the motherboard for the Z420 and Z620 are almost identical.  And, because many run the Z620 with only one processor that the Z420 in that case is even more identical.  Especially knowing that the really nice single processor builds for the Z420 version 2 and the single processor Z620 version 2 builds are truly the same.

Hence, Z420 version 2 with a single processor is near identical to and much cheaper than a single processor version 2 Z620.  Also, the select processors you'd want are both the same and both overclockable.  Maybe time to move on to newer hardware?  That is what my wife says......

[Hiatus]

Well, My weekend is ruined...
Research is usually my strong point and since every problem only occurs for the first time once, doing research on 10 year old hardware is usually quite straight forward. Someone else have usually done the hard part a long time ago and it's usually just a matter of finding and digging up the information. Usually.

Not in this case, though.
The closest I've been able to get is the official product update documents from Intel:

https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/5520-and-5500-chi...

I've read most of it now and as far as I can see it's supposed to include every single change done to the 5520 chipset from rev B3 to rev C2. But I can't seem to find the section about the RAM...

So, The research part isn't going that well.
And when it comes to someone else doing the hard work, I'm afraid in this case, You might be that someone.

If it turns out that this operation can be done with some know-how and a Raspberry Pi, this could mean a second life for the first generation Z600's that otherwise would be destined for the e-waste bin.
In 9/10 forum posts touching this subject (remember, 97% of all statistics are made up) the advice is to get rid of the old board and get a new one, and most people do...

That advice is never ever what the OP really wants to hear, Of course, And maybe the don't have to anymore if this turns out well.
Imagine "just get a Raspberry Pi and re-flash the chipset and your'e good to go with dual X56xx and wider memory support" instead...

I'm rooting for you, buddy!

Keep us posted!

Hiatus

[roadrunner321]

Yes, I'm in this for the fun. I don't really expect updating the bootblock will allow me to use registered memory, but I want to know understand exactly why that is.

I will update this thread if I succeed with the update.

[Hiatus]

I'm just as interested in failure as in success, so please keep us posted regardless of outcome! 🙂

Hiatus

[roadrunner321]

Didn't get too much work done over week-end, but I did manage to install Raspbian on the Pi.

Then I'm going to use this tutorial [1] to read the BIOS memory.

On my Z600 the memory is an Atmel AT26DF161, whereas on the Z800 it's an ST one. It' an important piece of information, as I haven't seen it online so far. Or maybe the Z600 v1 uses the Atmel and they changed to ST for later versions, I don't know. It doesn't make much difference I think, in terms of operation these 2 should work quite the same way.

Next I will use the Pomona SOIC8 clip to attach to my memory directly and read the flash contents using flashrom. Then I can probably do one of two things:

A) Use flashrom tool to rewrite the status register and modify the lock bits. These are supposed to protect the area in the flash memory where the bootblock resides. I've found in some related thread that the BIOS upgrade tries to flash the entire memory, but since the bootblock is in protected memory this never changes. I hope by disabling memory protection I can fool the flash utility to update the bootblock itself.

B) Use the more traditional approach to write a new memory chip with the image from the BIOS update package. I've found some information that this should work, but certain configs will change, like the MAC address of the integrated NIC.

I kind of favor option A, but I will keep a copy of the memory on another chip just to be sure. If method A fails, I will try with B.

So I still have work to do, I was hoping someone here with deep knowledge of the Z600 will be able to explain why B3 stepping does not support registered memory, this is the reason this thread exists in the first place.

[1] https://tomvanveen.eu/flashing-bios-chip-raspberry-pi/

[roadrunner321]

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@DGroves wrote:

i recomend not trying to override the bootblock with the v2 bios code as the chipset does indeed have numerous changes from the  B3 to the C2 revision to have/enable  ECC support, the CPU, Ram, and chipset must all have support for ECC, and the B3 revision appears to lack this support

you will be better served in my opinion  to simply aquire a v2 motherboard

---

@DGroves:
Did you stumble upon some piece of information I missed, about the B3 stepping lacking registered memory support? It doesn't seem to be in the 5520 IOH datasheet, and I couldn't find other sources of information.