Why not Registered ECC?

[markwill]

I read a comment here specifically recommending NOT to purchase registered ECC memory for the motherboard I have in mind.

"Do not buy Registered if you're using a supermicro X10 motherboard (or any other motherboard for LGA1150). You need Unbuffered."

Why is this? I will be buying from the tested list for the motherboard I have in mind, so this is not a compatibility issue. But I have the choice of "Registered ECC" or "ECC". What is the issue with registered ECC?

(Note: The comment is old, so no idea if it is still a factor. But I've seen so many folks here referring to docs from years ago that I am more respectful of such dated comments now :))

Thank you.

 

[Chris Moore]

The system board and processor must be compatible with Registered memory. If you try to use Registered memory in a system board that is not made for it, with a processor that doesn't support it, the system will not boot. It is possible to use Reistered ECC memory, you just need the correct system board and CPU to go with it. Here is a parts list:

Specific build changes to upgrade as high as 512GB of RAM

This is intended as a modification to the list of hardware I put together here: https://www.ixsystems.com/community/resources/specific-build-components-list-up-to-32gb-ram.109/ Be aware, this is a totally different system board with a totally...

www.ixsystems.com

 

[markwill]

Thank you, Chris. Yes, I understand that but I am only considering memory that is on the formal accepted/tested list for the specific motherboard I have in mind, to ensure I have no compatibility issues.

I have the choice of two two types for that board. Why is it advisable to avoid registered ECC?

 

[markwill]

The board I have in mind is the X10SDV-2C-TP4F.

On their product page, SuperMicro they have the following.

"Up to 128GB ECC RDIMM DDR4 1866MHz or 64GB ECC/non-ECC UDIMM in 4 sockets" (my assumption is that "RDIMM" is registered).

So, it's supported and (for me, at least) has a tiny benefit of allowing more memory. So, why is the recommendation in the comment at the topic of this thread to avoid registered ECC with any SuperMicro X10 board?

 

[Chris Moore]

If both the system board and processor are compatible with ECC Registered memory, there is no reason to avoid it. I use Registered ECC in both of my NAS systems, both of my ESXi hosts and in my personal workstation. Registered ECC is fantastic. The most likely reason for the warning is the possibility of buying memory that is not compatible and needing to send it back for a refund.

To be clear. The system board is not the only consideration. The system board I use can be configured with a CPU that does not support Registered ECC memory and in that case, the system would need to have Unbuffered memory instead. It is the combination of the CPU and the system board that must be looked at together to determine compatibility.

 

[markwill]

Cool - thanks. Seems like the original statement is a bit of a sweeping statement so I really appreciate the clarification. Thank you again.

 

[Chris Moore]

If you want to post the exact part numbers you are looking at, I am sure that someone here would take a look at it to double-check.

 

[markwill]

Sure and thank you.

Motherboard / CPU : X10SDV-2C-TP4F
Memory (I'm likely to purchase) : MEM-DR416L-CL07-ER26

 

[Chris Moore]

X10SDV-2C-TP4F

I went and looked that board up. It has an integrated CPU. I didn't recognize that. It is one of the exceptions to the rule. Yes, absolutely compatible with Registered ECC.

 

[markwill]

Yes, sorry I wasn't more clear (and that was why I wasn't freaking out about the CPU, though the point you made was obviously a valid one generally). Honestly, I'm just starting to look at my first NAS build and I have been surprised at how low cost ECC is. Seems like a bit of a no-brainer to me for a FreeNAS build :)

Thank you again, Chris. Your responses are greatly appreciated, sir!

 

[Chris Moore]

MEM-DR416L-CL07-ER26

I hate to see anyone spend that much but yes, this should work. Supermicro says that the board supports memory speed up to 1866MHz, so you could save some money with slower memory.

 

[Chris Moore]

If you are willing to consider used hardware, you can save significantly there. You might want to take a look at this parts list:

Specific build changes to upgrade as high as 512GB of RAM

This is intended as a modification to the list of hardware I put together here: https://www.ixsystems.com/community/resources/specific-build-components-list-up-to-32gb-ram.109/ Be aware, this is a totally different system board with a totally...

www.ixsystems.com

 

[markwill]

Well, this is like a game of wack-a-mole. No sooner had I closed on that decision and there's another one :)

Good spot on the motherboard note on speed. Totally missed that.

That said, the slowest approved registered ECC memory seems to be 2400. Providing no major costs concerns (this still seems reasonable to me :)) I'm going to prioritize the approved/tested list over saving a few dollars on something that is not on the list, even if I am throwing away a few hundred Mhz.

I assume that makes sense, yes?

And, yes, I will take a look at the used hardware, with thanks.

 

[Jessep]

Chris already answered your question, just adding some context for other readers.

"Do not buy Registered if you're using a supermicro X10 motherboard (or any other motherboard for LGA1150). You need Unbuffered."

This key in this quote is the LGA1150/1151, x10 boards with that socket require unbuffered. x10 is a generation not a specific board type. So you can have Xeon E3 LGA1150 (unbuffered), Xeon E5 LGA2011R3 (registered), or embedded (either). It can get more complicated than that with LR DIMMs, 3DS DIMMs, the various forms of embedded CPUs, and the multitude of Supermicro board generations.

 

[gnrlpatton]

Well, this is like a game of wack-a-mole. No sooner had I closed on that decision and there's another one :)

Tell me about it! I'm trying to put my system together. After the 2nd iteration of parts, I'm now seeing that my Motherboard (Gigabyte C246M-WU4) doesn't support Registered memory. Well, guess what I have for memory - 32GB Crucial DDR4 ECC Registered. Ugh.

So, back to the drawing board. I "think" my MB/CPU combo is good, CPU is the Intel Core i5 9600K, which is on the compatible list of the Motherboard. Now I just need to find correct memory for it. The CPU will support DDR4-2666, so I'm thinking this one: Crucial 32GB Kit (16GBx2) DDR4 2666 MT/s (PC4-21300) DR X8 DIMM 288-Pin Memory - CT2K16G4DFD8266

Anyone see any issues with this trio?

Motherboard: Gigabyte C246M-WU4
CPU: Intel Core i5-9600K (w/ integrated graphics)
RAM: Crucial CT2K16G4DFD8266 - 32GB

Fingers crossed this is the final combo. This was supposed to be the easy part of the build.

Thanks,
Kevin

 

[jgreco]

Chris already answered your question, just adding some context for other readers.



This key in this quote is the LGA1150/1151, x10 boards with that socket require unbuffered. x10 is a generation not a specific board type. So you can have Xeon E3 LGA1150 (unbuffered), Xeon E5 LGA2011R3 (registered), or embedded (either). It can get more complicated than that with LR DIMMs, 3DS DIMMs, the various forms of embedded CPUs, and the multitude of Supermicro board generations.

Well, in context, the statement is simply wrong. "X10" refers to boards that support two full generations of CPU architecture, with a dizzying array of possible memory options. Unbuffered actually won't work in a lot of X10 boards.

Supermicro Motherboard Part Number Guide

BigDave recently posted a link to Supermicro's part number guide which MoB then identified the current copy of. I'm reposting this here in a slightly redigested format. The original UP and original DP guides are here. Supermicro motherboards are logically named based on type and features. Up...

www.ixsystems.com

What you really need is to look at what kind of memory the board claims to support, PLUS what kind of memory the CPU you wish to use supports, and then take the union of that.

For example, the X10SRL board (clearly an "X10") supports RDIMM and LRDIMM but an E5-1650v3 does not support LRDIMM, so you may only use registered on X10SRL+E5-16xx v3. However, the E5-26xx v3 does support LRDIMM, so you may use RDIMM or LRDIMM on the X10SRL there. No combination supports unbuffered.

Someone didn't realize what the "X10" means and made a far-too-broad blanket statement. Where is this posted, anyways? I am tempted to go correct it. It is correct to say "any LGA1150-based X10 board" ... but not "any X10 board (or other LGA1150)"

 

[Evertb1]

Anyone see any issues with this trio?

Motherboard: Gigabyte C246M-WU4
CPU: Intel Core i5-9600K (w/ integrated graphics)
RAM: Crucial CT2K16G4DFD8266 - 32GB

Well... The RAM is not ECC and the CPU does not support ECC. A lot of people seem to think that ECC RAM is important for FreeNAS/ZFS.

 

[danb35]

A lot of people seem to think that ECC RAM is important for FreeNAS/ZFS.

ECC RAM is important if you care about your data, irrespective of the OS or filesystem. There's nothing about FreeNAS or ZFS which make it any more desirable than it would be anywhere else, FUD about the "scrub of doom" notwithstanding.

 

[Evertb1]

CC RAM is important if you care about your data, irrespective of the OS or filesystem.

True, I have been running Windows Server 2012 essentials with ECC RAM before my switch to FreeNAS. But I tried to keep my response within the context of FreeNAS. Though I could argue that if you take the effort to go with an OS like FreeNAS and a filesystem like ZFS you might as well take the next step in data safety. Otherwise I don't see the point. Because no mather how much I like FreeNAS it is not your average consumer product. And there are a variety of NAS flavors available these days that are less demanding. Not as good of course :) .