Here are modded BIOSes for these Asus X79 boards:
- P9X79 Deluxe (based on v4801)
- Rampage 4 Extreme (based on v4901)
- Rampage 4 Gene (based on v4901)
All have NVMe support, latest uCode and hidden System Agent Configuration and PCI Subsystem Settings menus unlocked. So bifurcation support included.
All share the same properties:
- Tested with Asus Hyper M.2 X16 v2 mounted with 2 Corsair MP510 SSDs. Adding third or fourth SSDs did not succeed but I only had a Samsung 970 EVO SSD which seems to be somewhat incompatible with Corsair SSDs.
- 2 SSDs can either use 8x slot bifurcated to 4x4x or 16x slot bifurcated to 8x8x, 4x4x8x or 8x4x4x. 4x4x4x4x may also work. SSDs may have to be mounted on different Hyper card ports depending on the bifurcation setting.
http://s000.tinyupload.com/?file_id=06635992564454953281
Have fun!
Hello.
Can you reup the link please? Seems like it is not available anymore… 
@Joe_Hallenbeck - That site is down right now, link probably still good once site (my favorite) comes back online.
In the meantime, @biosphere - can you provide a mirror, thanks! 
My own Hyper V2 quick testing info
[REQUEST] Bifurcation Asus x99-a II - 5820k (2)
I’m using a P9X79 Deluxe with Hyper M.2 x16 and 2 M.2 SSDs. I did the BIOS flashback using the P9X79 file in the zip, but I’m not sure if it actually flashed it or not. The blue light blinked for a few minutes, and then stopped, so I turned on the machine. I noticed some of my BIOS settings had changed, but I don’t see any new options. CSM is set to disabled. I could only ever see 1 drive M.2 when I booted from my SATA drive, and after I installed Windows to the NVMe drive, there was no way to boot to the NVMe install. What am I doing wrong?
Downloaded a tested and It works well.
BRiAN: What type of OS did you instal?
I ended up finding a BIOS that Lost_N_BIOS made on another thread. That one worked the first time around. Maybe I did something wrong the first time I tried using this one. Either way, I’m not going to mess with it since it’s working fine with Lost_N_BIOS’s upload. I should have mentioned that sooner so you didn’t waste your time trying it. Thanks for helping.
Glad to hear that. Can you send me link to the BIOS which is working for you please? 
Ok I have got some questions.
I have got ASUS P9X79 Deluxe Mainboard. There are 4 PCIe ports (3 x PCIe x16 and 1x PCIe x8). They are divided by color on the mainboard. Two of them are blue and two are grey.
I am using ASUS HYPER M.2 CARD V2 adapter to PCIe x16 with two Baracuda 510 (1TB) SSD M.2 drives.
There is a problem during instalation of Win7. Instalation disc is updated with NVMe support updates KB2990941-x64 and KB3020369-x64.
Both drives are recognized by BIOS (Flashed BIOS from the first post of this thread) as PATA discs. W7 also see them and I can use them in OS, but only during instalation of W7 I can choose one of them. Second one doesn’t appear. It leads to the problem, that I can instal the fresh W7 only on one of the Barracudas, because I don’t see second Barracuda M.2 in menu with offer of the suitable HDs for the instalation.
I would like to know why I see only one of them during the instalation, even If both drives are recognized by BIOS and by instaled OS.
Second problem is, when I change the PCIe slot and ASUS M.2 adapter (I have to use grey one which is x8 and bifurcated in BIOS to x4x4 - It is third slot from the top on Mobo) I place to the lowest PCIe slot, which is blue and natively works as x16, then no matter what kind of bifurcation settings I use (x8x8, x4x4x8,x4x4x4x4), I see only one of the M.2s in BIOS as PATA, same in W7 (also I see only one Barracuda), but during the instalation of W7 I don’t see any of them. Of course, I am using the same updated instalation disc of W7.
Can anyone help me solve the problems please?
Problem solved accordingly to the thread with same findings as was mentioned in the post #283. I have to set Barracuda 510 to possitions 1 and 4 in the ASUS adapter card and then placed ASUS adapter in to the fourth (blue) PCIe port on MOBO. Set Bifurcation 8x8 in BIOS and everything works well. The only difference I have seen is, that my Barracuda 510s work with cca 1200/1900 seq/write no matter which of the slots I use…
Can anyone reup please? It seems like tinyupload has been down for 1~2 months already (edit: OVHcloud had a fire)
Does anyone still have a copy of this bios?
Hi @Joe_Hallenbeck @Brian @biosphere - Can you please upload the P9X79 Deluxe Bios you have, pretty please? There’s now a attach file button in forum reply, so hopefully is the last time anyone bugs you for re-upload! Thank you in advance!
This Bios for the P9X79 Deluxe have Bifurcation and i hope the option " Above 4G Encoding ", i search for use a Tesla M40 for rendering the graphyx output in a GT-710, my old GT-680 are DEAD and VGA market is completly crazy.
Is these option Unlocked, and Anyone have Tested? ( and the links do not work… some alternative download link? )
Please
The user in 1st post never updated the links, no one ever on this thread shared this files anymore, the tool AMIBCP 4.x will work on this bios type (AMI Aptio IV core),
so every user can unlock this features and safely use the Asus BFB method, setting the access lever to USER instead of Default in parent menus strings.
NOT changing any values of the strings as this can break the bios (It requires additional methods), ONLY the access type.
I have put a Bios like This and i have Try the Option
Above 4G for the 64Bit PCI-E Addressing and test the Tesla M40, the Mobo Boot, but there is no way to have a Video Output, the Screen are Black, the Mobo make Boot and load the OS, i have logged using Team Viewer and some PCI-E card Network Audio Usb, and the Secondary Video card too (GT-710 on 8x PCI-E) have the Error Code 43.
Anyone know how to made work these type of configuration ? (Some Tips to try)
(I have Switched off some of PCI-E integrated board but no difference, BLACK SCREEN)
Note: If you use the Tesla M40 and you no activate the option Above 4G, the Mobo Lock and Beep 8 time…
Yeah need integrated graphics or another gpu, if you look up "tesla m40 for gaming" there should be many posts telling you exactly what to do in this exact situation