[GUIDE] Adding Bifurcation Support to ASUS X79 UEFI BIOS

Sorry for the late reply,
Not knowing what or how many your connecting to you PCIE I recommend either buying a ~300 EUR+ card that does PLX/PFX/PEX lane switching (optional M.2 Key M to PCIe x4 NVMe Adapter cables); or switch platforms to something like amd tr4 threadripper, or x299(cannot do hardware NVME raid).
I have not tried the Above 4G setting. As for the other unlocked BIOS settings it is quite a mine field.

Thanks for your reply anyway.
Could you recommend anything except boards shipped by c-payne.com? 350 EUR for the board, +re-driver cards and SAS cables to get the config out of the pc case… Well, it’s a serious investment ))

Other observations: I can bifurcate x16 slot (third from cpu socket) and it works more or less ok (except for the Tesla K40 that blue-screening periodically in the bifurcated slot but works ok via USB riser in PCI 2.0 x1 slot). However, when I’m trying to bifurcate x8 slot (to the pair of the x4 links) Win 10 shows unrecognized device for the second x4 link and can’t install drivers for anything: tested with several GPU-s, WiFi card, NVME with adapter. Did anyone tried the x8 slot bifurcation with other type of re-driver cards than I’m using - like dual M.2 cards?

I see in the bios the 8x slot has the x4x4 option. Anyone try that slot to use 2 NVMe drives ?

I am thinking about a card like this



@chuckbam Did you end up getting 3 or 4 NVME drives working off this adapter?

the adapter only holds 2 NVME drives. I did not buy it yet

@chuckbam Quote from your link: Supports 4 X 2280 NVMe M. 2, I think the card might have 2 sides with 2 drives each. However 2 of them will probably work in x4x4 bifurcation.

@JackSted ,

Your right holds 4 drives.

@JackSted ,

So there is a electrical issue with 4x4x4x4x on the first two 16x slots but the 4x4x works on the bottom 16x (8x) slot ?

Chenyang Dual 2X NVME M.2 AHCI to PCIE Express 3.0 Gen3 X8 X16 Raid Card VROC Raid0 Hyper Adapter (Only Supports motherboards with Detachable PCI-E Channels)

From reading back to page one, trying to skip through flashing and installing Windows replies,

I have one question. Does the Bifurcation Support to ASUS X79 UEFI BIOS work?

Thank You

@JackSted I’m having a hard time finding the link for your p9x79 bios file, is the file still up?