PCIe Bifrucation

[osar]

Hello there,

 

I am currently building a new computer. The computer will mostly be used for I/O heavy applications in a research context. 

I would like to use a ASUS Hyper M.2 X16 PCIe 4.0 X4 Expansion Card to run four M.2 SSDs. To use such an expansion card, the motherboard needs support for PCIe bifrucation. Quite naively I thought that this is common feature supported by most motherboards and just bought a Gigabyte B560M Aorus Elite which does not allow me to enable bifrucation. Therefore I am now searching for another motherboard that does support bifrucation and in my case an Intel i5 11400. 

 

Sadly I could not really find much regarding this feature on the product pages provided by the manufacturers. Maybe someone in this forum has some experience with this and can help me.

 

Maybe we can also start a table in this thread collecting motherboards with bifrucation support ?

 

 

[HanZie82]

If there's not gonna be a better solution. You could always look into motherboards that have or come with such PCIe M.2 slot things.

Logic would dictate they need bifurcation too.

[osar]

That was my thought as well. But that seems not to be true. The B560M Aorus Elite has one PCIe 4.0 4x and one PCIe 3.0 4x slot, but I can not find a option in the BIOS to enable it to split the PCIe 4.0 16x into 4x PCIe 4.0 4x.

[Dreckssackblase]

from what I could find with some googling it looks like bifurcation is a feature of the x or z type chipsets and not avaiable on b type boards.

[Jurrunio]

15 minutes ago, osar said:

That was my thought as well. But that seems not to be true. The B560M Aorus Elite has one PCIe 4.0 4x and one PCIe 3.0 4x slot, but I can not find a option in the BIOS to enable it to split the PCIe 4.0 16x into 4x PCIe 4.0 4x.

Single M.2 slot B560 boards do not have PCIe bifurcation, 11th gen gets dedicated lanes from the CPU to an M.2 slot. Even more M.2 slots are not indicative, you can have M.2 connected to the chipset as well.

 

There's this from Asus

https://www.asus.com/support/FAQ/1037507/

 

but other brands seem to require looking up each board's own manual. 

[Radium_Angel]

Might be easier to buy a PCIe card that supports BiF natively. I have two such cards in my Ivy Bridge workstation, they work just fine

[osar]

On 12/1/2021 at 4:54 PM, Radium_Angel said:

Might be easier to buy a PCIe card that supports BiF natively. I have two such cards in my Ivy Bridge workstation, they work just fine

Can you share the cards you are using ? I couldn't find one, at least with PCIe4.0 support. I remember that Linus at some point hat these honey badger cards, but those are quite expensive.

 

On 12/1/2021 at 4:38 PM, Dreckssackblase said:

from what I could find with some googling it looks like bifurcation is a feature of the x or z type chipsets and not avaiable on b type boards.

yes you are right about that. From what I have read Intels 11000 series chips seem not work for running these m.2 extension cards, since they do not support a split into four 4x slots, the max number of m.2 slots one can use with Intel 11000 series chips seems to be 3 when splitting the 16x slot into 8x/4x/4x.

 

Should have gone with AMD I guess. 

[Radium_Angel]

1 hour ago, osar said:

Can you share the cards you are using ?

https://www.amazon.com/gp/product/B07WDM3H9Z/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1

 

A pair of these. They are not cheap, but worth every penny.