Xeon 34xx + registered ECC memory in a non server 1156 board? Works?

[freifacht]

Hello everybody,
i'm already a member in the german section. Didn't know i have to register again for "worldwide"
Anyway: hello everybody

Maybe i can get some advice or help

I am assigned to build a nice and reasonable priced little workstation.
I chose a Socket 1156 board, most likely the ASUS P7P55D.
One requirement the system has to fulfill is that it should have 8 GB RAM with the option of updating to 16GB.
So plugging in two 4GB modules seems to make sense because this would leave two RAM sockets free for another two 4GB modules.

Now officially the "consumer" 1156 boards support "regular" i5 and i7 CPUs and non registered memory.
But most of you already know (i guess) that the X34xx server CPUs can be used as well.
Now the advantage of those CPUs is that the memory controller is integrated in them.
Also they suppport registered ECC memory.

My question is: can registered ECC memory be used in a "Xeon 34xx + P55 board combo"?

unregistered regular memory costs apprx. 160 EUR per 4 GB module.
registered ECC memory costs apprx. 110 EUR per 4 GB module.
So if this worked i could save my "client" about 200 EUROs.

Is there anyone out there who could provide some information?

many thanks in advance

 

[GhislainG]

To use Registered ECC memory, you need a motherboard and CPU that support it, e.g., the ASUS P7F-E LGA 1156 (8 memory slots for up to 32GB) and, as you already mentioned, a Xeon 3400 series processor.

Edit: The Intel 3420 chipset is used on single processor motherboards.

 

[freifacht]

but this board has only six slots (what imho doesn't make any sense anyway because socket 1156 has only two memory channels)

the confusing part is that there is also a board with 3420 chipset which (as far as i understand it) does not support registered memory.
So this leads me back to the main question: is memory support restricted by the CPU only or by CPU and mainboard combo...

It was this article http://ixbtlabs.com/articles3/cpu/intel-xeon-x3450-p1.html where the author talks about using registered ECC memory with Xeon 34xx. But he is not very precise about the mainboards.
Anyway, that article lead me to the idea of eventually combining x34xx CPUs and registered memory in a P55 board.
Still waiting for its author to answer my question.

 

[GhislainG]

You are correct about the number of slots. All Intel 34xx chipset motherboards seem to support ECC Registered memory (RDIMM) as long as you use a Xeon 3400 series processor: http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2010200302+1071349628+1197712658&QksAutoSuggestion=&ShowDeactivatedMark=False&Configurator=&Subcategory=302&description=&Ntk=&CFG=&SpeTabStoreType=&srchInDesc=

ECC registered (RDIMM) or Un-Buffered (UDIMM) is not supported when using an i7 processor.

 

[freifacht]

so RDIMM is registered Memory? Right?
But this is from ASUS: "P7F-X family don't support RDIMM, the rest of models P7F-M, P7F-E, P7F-C family support RDIMM."
So this statement

All Intel 34xx chipset motherboards seem to support ECC Registered memory (RDIMM) as long as you use a Xeon 3400 series processor

is not exactly correct.

Now what puzzles me is this: P7F-X boards are 3420 chipset. But nevertheless it does not support RDIMM, unlike the other "3420 chipset boards". That means that the chipset seems to be not the only factor whether a specific memory works or not...

So couldn't it on the other hand be possible that registered ECC works with P55 boards?
Just remember that X34xx CPUs are not in the official supported list but still they are said to run fine in P55 boards.
So "officially supported" and "real life supported" might be two different pairs of shoes...

 

[GhislainG]

I missed the lack of RDIMM support for the P7F-X because I was searching for RDIMM motherboards only. However it still supports ECC emory (though RDIMM is preferred) when paired with a Xeon 3400 series processor.

So couldn't it on the other hand be possible that registered ECC works with P55 boards?

P55 based motherboards don't include the additional logic required for RDIMM. I don't know if a P55 based motherboard with a Xeon 3400 processor works with ECC (UDIMM), but for a workstation I'd probably use RDIMM.

 

[Tony_Scarpelli]

ECC is error checking and correcting. It has nothing to do with buffered or unregistered. non ecc is usually unregistered. ECC can be either.

Buffered memory, sometimes called registered ram has a register in it and allows for high wattage large memory usage. It has a wait state so it is slower than non registered memory. Also ECC is about 15% slower than non ECC ram. Ram has 8 chips one for each bit, ECC ram has 9 chips 8 plus one for the parity bit.

 

[Ov3r23]

Hello, I have the same question: does ECC functionality work in a system with Intel DP55KG P55 motherboard + Xeon X3450 Processor + ECC 1333 DDR3 memory?
this will be a very nice cost effective solution for my workstation

thank you

 

[crazyjpeters]

I'm also interested in trying a 34xx chip with udimms. Can anyone confirm whether this would work? Does the cpu determine whether ecc will function, or is there something additional at the mobo level that determines if 34xx + ECC will even operate in a p55 board? (I have a gigabyte p55-ud4p that I'd like to use as a workstation with ecc memory)