SuperMicro C7C242-CB-M and X11SPM bifurcation?

[emsicz]

I've got ASUS HYPER M.2 X16 Gen4 card laying on the desk and I'm looking to buy C7C242-CB-M board to use it with. I can't find anywhere whether the board supports bifurcation? The reason I chose this board is because I need mATX form factor and ECC support and this was the only board of theirs I found.

 

[Dice]

Usually it is discussed in the motherboard manual.
I open the manual and search for bi-furcation/furcation/4x4 something along those lines.
C7C242-CB-M did not give any results back. I doubt it supports it, as this is in ultra desktop territory.

What about their server series?

 

[emsicz]

Yep, in the manual I wasn't able to find anything. I didn't find any server series board that would fit into mATX case. To be fair, I'm having serious issue trying to find any mATX board with bifurcation support. Like any board, any vendor.

 

[Patrick M. Hausen]

You can always open a ticket with Supermicro support and just ask. They are quite friendly and responsive.

Home Page

webpr3.supermicro.com

 

[Ericloewe]

The reason I chose this board is because I need mATX form factor and ECC support and this was the only board of theirs I found.

Did you miss the entire X11SC* line or is there some additional requirement? Is it an availability thing?

That said, with an LGA1151 CPU, you're absolutely not going to get the x16 slot bifurcated down to x4/x4/x4/x4. The supported options are x16, x8/x8 and x8/x4/x4. Only the higher-end stuff supports x4/x4/x4/x4. You can also get a card that uses a PCIe switch, or alternatively use only three of the four M.2 slots on your adapter card (which three is an interesting question you can figure out through trial and error).

 

[emsicz]

I opened a ticket with them.

 

[emsicz]

Did you miss the entire X11SC* line

Yes, thanks.

 

[emsicz]

Did you miss the entire X11SC* line or is there some additional requirement? Is it an availability thing?

That said, with an LGA1151 CPU, you're absolutely not going to get the x16 slot bifurcated down to x4/x4/x4/x4. The supported options are x16, x8/x8 and x8/x4/x4. Only the higher-end stuff supports x4/x4/x4/x4. You can also get a card that uses a PCIe switch, or alternatively use only three of the four M.2 slots on your adapter card (which three is an interesting question you can figure out through trial and error).

I did more research and found this board: https://www.supermicro.com/en/products/motherboard/X11SPM-TF?locale=en

According to the manufacturer, it comes with 2 x16 PCI-e 3.0 slots. The manual doesn't mention bifurcation, so I'll ask them again if this board maybe could do that.

 

[Dice]

I did more research and found this board: https://www.supermicro.com/en/products/motherboard/X11SPM-TF?locale=en

According to the manufacturer, it comes with 2 x16 PCI-e 3.0 slots. The manual doesn't mention bifurcation, so I'll ask them again if this board maybe could do that.

The simpler X11SSL for example, does not support bifurcation.
IIRC, the X11SSM did.
The lower in the product stack, the less likely it will support bifurcation.

 

[Ericloewe]

The simpler X11SSL for example, does not support bifurcation.
IIRC, the X11SSM did.
The lower in the product stack, the less likely it will support bifurcation.

Same platform and firmware. 99% sure they’re the same, unless it’s a stupid firmware restriction by Intel on the C2x2 PCHs.
But again, they don’t do x4/x4/x4/x4, the PCIe root controller on the LGA115x CPUs just can’t do it. No way around this without PCIe switches or a higher-end CPU. My Xeon E5-1650v3, for instance, is considerably older but bifurcates all the way down to x4/x4/x4/x4 just fine (motherboard firmware doesn’t expose the setting, even though it exists, so I had to manually edit the binary UEFI settings to enable it).

 

[Dice]

Same platform and firmware. 99% sure they’re the same, unless it’s a stupid firmware restriction by Intel on the C2x2 PCHs.
But again, they don’t do x4/x4/x4/x4, the PCIe root controller on the LGA115x CPUs just can’t do it. No way around this without PCIe switches or a higher-end CPU. My Xeon E5-1650v3, for instance, is considerably older but bifurcates all the way down to x4/x4/x4/x4 just fine (motherboard firmware doesn’t expose the setting, even though it exists, so I had to manually edit the binary UEFI settings to enable it).

I had confused X11SSM with X11SSH-LN4F.
That one is confirmed by "local" retailer to do 4x4 on SLOT5.

What motherboard do you have on that 1650v3´?

 

[Ericloewe]

What motherboard do you have on that 1650v3´?

Asrock X99 WS. Would not recommend at all prior to the latest available firmware version. I had to run 1.x for years (I think it didn't even have an NVMe driver!) until they released an update for Spectre/Meltdown that "accidentally" updated the firmware to some internal beta version or whatever, along with the updated microcode - all 2.x and the previous 3.x versions just did not like my setup, it seems, despite the RAM being explicitly listed as compatible.
When I later upgraded to 64 GB of RAM, I gave very little thought to said list after that experience.

 

[Etorix]

That said, with an LGA1151 CPU, you're absolutely not going to get the x16 slot bifurcated down to x4/x4/x4/x4. The supported options are x16, x8/x8 and x8/x4/x4. Only the higher-end stuff supports x4/x4/x4/x4.

Gigabyte C246N-WU2 supports x4x4x4x4 bifurcation on its sole PCIe slot, so it should not be a CPU limitation.

I did more research and found this board: https://www.supermicro.com/en/products/motherboard/X11SPM-TF?locale=en

A Xeon Scalable board most likely supports bifurcation all the way down from x16 to x4x4x4x4, but is it sensible to go C621 and Xeon Scalable just for using an Asus Hyper M.2 card?

 

[Ericloewe]

Gigabyte C246N-WU2 supports x4x4x4x4 bifurcation on its sole PCIe slot, so it should not be a CPU limitation.

They only seem to claim x8/x8, which is very typical (and in fact happens anyway when you have two physical x8 slots, it's just switched automagicaly by detecting the presence of a card in the second slot).

A Xeon Scalable board most likely supports bifurcation all the way down from x16 to x4x4x4x4, but is it sensible to go C621 and Xeon Scalable just for using an Asus Hyper M.2 card?

It does feel like overkill and like we're looking at a solution looking for a problem. If that's the case, Xeon E5 v3/v4 stuff is very cheap these days and still perfectly viable. The Dell R630/R730 line has bifurcation options exposed, for instance, and they're everywhere on the used market.

 

[Etorix]

They only seem to claim x8/x8, which is very typical (and in fact happens anyway when you have two physical x8 slots, it's just switched automagicaly by detecting the presence of a card in the second slot).

I have the board (as a desktop hackintosh). The BIOS menu allows to split the single x16 slot (miniITX) as 8/8, 8/4/4, 4/4/8 or 4/4/4/4, which goes beyond the usual "automagic 8/8" of ATX/mATX boards. I have not tested the last option but I assume Gigabyte would not bother writing explicit BIOS entries for configurations which do not work.

 

[Ericloewe]

Interesting... Any PCIe switches on that board? If not, maybe intel added that option for (some?) Coffee Lake...

 

[emsicz]

It does feel like overkill and like we're looking at a solution looking for a problem. If that's the case, Xeon E5 v3/v4 stuff is very cheap these days and still perfectly viable. The Dell R630/R730 line has bifurcation options exposed, for instance, and they're everywhere on the used market.

If I understood correctly, the R630/R730 are rack mounted servers. I'm looking for mATX board so it fits into mATX PC case. It's my home office server, it sits in my office and I'll need it quieter than a rack unit lol. I was thinking of getting said X11SPM-TF board with Intel Xeon Silver 4208. Where I live, the costs for this builds would be as follows (prices w/o VAT)

SM X11SPM-TF	US $555
Intel Xeon Silver 4208	US $452
6x Samsung 16GB DDR4-2933 M393A2K40DB2-CVF	US $640

I do already have a build made out of consumer hardware (MSI gaming board, i5-10400F, random non-ECC memory). I'm thinking the noise won't be an issue for me, but I'm basing that off the fact that this particular Xeon has a TDP of 85W. I'm thinking it's close to that of the 10400F (65W) and the server is not exactly busy apart from some peak hours over night where I won't care much about the noise it makes.

Also I could get Xeon W-1270E or Xeon Silver 4310 for only about 10 bucks more, but these have different sockets.

The reason I want the ASUS HYPER card in there is because one of the projects I'm working on is analytics tool and I could really use some super fast scratchpad storage. I already have four NVMe drives laying around and using this would considerably reduce turnaround times for the thing to run and get results. But yeah also I'm spoiled and I want the thing to be in there so there's that.

 

[emsicz]

SuperMicro has replied that SM X11SPM board does indeed support all kinds of bifurcation for both of it's PCIe 3.0 x16 slots and it is mentioned in the manual. I discovered that if I do a Ctrl+F search in their manuals after they open, nothing gets found as the file is still loading. If I wait a while, the term bifurcation is finally found at page 86 under IO Configuration. To be exact, the board has following options:

IOU0 (II0 PCIe Br1)
This item configures the PCI-E port Bifuraction setting for a PCI-E port specified by the
user. The options are x4x4x4x4, x4x4x8, x8x4x4, x8x8, x16, and Auto.
IOU1 (II0 PCIe Br2)
This item configures the PCI-E port Bifuraction setting for a PCI-E port specified by the
user. The options are x4x4x4x4, x4x4x8, x8x4x4, x8x8, x16, and Auto.
Chapter 4: BIOS87
IOU2 (II0 PCIe Br3)
This item configures the PCI-E port Bifuraction setting for a PCI-E port specified by the
user. The options are x4x4x4x4, x4x4x8, x8x4x4, x8x8, x16, and Auto.

Somehow I think this must be configuring PCI lanes regardless of physical ports on the board, because I'm confused how could the PCI-E 3.0 x8 port be configured into anything mentioned above. Other than that, I've also thrown in SM's SATA DOM drive to serve as boot media and their miniSAS to SATA breakout cables.

Additionally, their support has stated that they didn't explicitly test the ASUS HYPER card, so they gave no guarantee. I'll see what happens when it gets here.

 

[NugentS]

I use an Asus Hyper card on an X10 for a while. I took it out and replaced with a AliExpress special because the Ali card was shorter. The Asus card is quite long and was getting in the way.
It worked just fine though

 

[emsicz]

Just checking back - I've got the X11SPM-TF working with the ASUS Hyper M.2 Gen4 in either of the two PCIE X16 slots (both are configurable into 4x4x4x4 in BIOS and can be configured independently and fully with any other PCIE slot on the board consumed -- provided the CPU in the slot has enough lanes) and as @NugentS said, it works just fine. I have also ordered NVME host card from Ali, because of the shorter length.