Part Looking For Mini ITX Mobo + PCIe 4.0 x16 bifurcation cable (maybe) - Good idea?


Average Stuffer
Original poster
Sep 21, 2017
Hello Everyone,

Wondering if something like this would be possible:

Looking to build a SFF Intel (probably i5-12400) based PC, though I might consider AMD CPU instead. Looking to use a Velka 3 case.
Any recommendations on Intel or AMD side for Mini ITX motherboards that support bifurcation?

Also, looking for the PCIe 4.0 x16 bifurcation cable so that I can connect both a Radeon RX 6400 vid card (I don't need high performance - just a casual gamer) & an old Mellanox ConnectX-3 10Gbit Ethernet card to access my OMV Server at 10Gb.

Also, would there be power issues in this scenario? Since the RX 6400 needs to draw all it's power from the PCIe port & not really sure how much power the ConnectX-3 card draws from the port.

Also not sure if it matters but looking to use Linux most likely (latest Pop OS!) instead of Windows.



Master of Cramming
Jun 17, 2018
Just thought I'd give you another option, instead of bifurcation.

This Tiny 10GbE NIC Slots Into an M.2 Port | Tom's Hardware (

There are Linux drivers for it too.

Depending on how much DIY you're willing to do, you might be able to dremel out the vents above the graphics card slot and fit the Ethernet port there, which would then give you the space for a faster 2 slot graphics card. Something like an RTX 3050 could almost double your framerates, albeit at more than double the power consumption.
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Average Stuffer
Aug 26, 2020
On the AMD side (someone correct me if I'm wrong) I beleive all B550 boards support bifurcation.


Master of Cramming
Jun 17, 2018
Thanks AlexTSG, however I'm looking to use both M.2 slots on the mobo for SSD's.

Ah okay.

I checked the MSI B550-I Gaming Edge motherboard I'm using, and it does support bifurcation.

The BIOS option is called "PCI_E1 Lanes Configuration" and the options are:
- Auto​
- x8 + x8​
- x8 + x4 + x4​
- x4 + x4 + x4 + x4​
They mention this being an option to use with their MSI M.2 Expander card, although I'm sure it would work for your purposes with an appropriate riser.

Hopefully some others with Intel boards can check their BIOS settings and let you know if a similar option is available.
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