Thanks for the reply, but I managed to get it working last night. More importantly, thanks to you and everyone else here for there work, it's top notch, and I wouldn't have attempted this without this thread.

@tbonius - Great to hear you got it all setup and working now
And of course, you're welcome!

I updated first post.
@Lost_N_BIOS I would like to ask for help with bifurcation support my other board : LINK
Thanks !

@agentx007 - Thanks, I will check the other thread and let you guys know if I can help

Greetings and salutations;
This thread has been a great resource for keeping my x79 system running with these newer SSD's, so I'm hoping that you can help with my current roadblock.

I have a ADATA M.2 SSD on a card (in the bottom PCI-Ex slot) and have Windows 10 installed and booting fine.
I bought 4 Intel 660p 1TB SSD's and the infamous Asus Hyper M.2 x16 card V2. Before flashing to the 4801 bifurcation bios, the system recognized one of four drives.
I've just flashed the 4801 bifurcation bios and set the top PCI-Ex slot to x4x4x4x4 in the bios... I think, that page makes little sense to me.
But now the system recognizes two of the four SSD's. I can't do much else with them. RAID options don't work with Disk Management (spanning only offers 1TB instead of 2TB?) and I would really like to get all four into a RAID0 anyway.

Is there a post I should look to in this thread that outlines how to set the bios correctly? Any help would be greatly appreciated as I don't want to upgrade this relic... the only things I've had to upgrade over the years are the video cards and I like the option of having two GPU's running at full x16.

BTW I installed IRST after initially installing the Hyper V2 and it first showed 1 drive at 2000/mbs and then later at 4000/mbs transfer but now the IRST manager 'crashes'/fails to launch... not sure if that is important or not, but thought it worth mentioning.

Thanks
Orbserver

@Orbserver Which slot you are using for Hyper v2 card ?
Because bottom slot on X79 Sabertooth is x8 max.

@agentx007 I first attempted this with the V2 in the 2nd farthest (from the CPU) x16 slot, and one SSD was detected. So I could assume that it was at least getting power and some (at least x4) lanes. Then I moved the GPU down and put the V2 in the x16 slot nearest the CPU. And lo, two SSDs were detected. That was after flashing the BIOS and bifurcating the slot (I think). I say that because I guessed at which IOU slot setting to change and the fact that the GPU is working... I'm thinking that wouldn't be possible if the slot settings for it were bifurcated? It was IOU2. I set it to x4x4x4x4 and all the PCI Gen #'s to 3... originally they alternated from 3 to 2 to 3 to 2.

Have you managed to get a V2 card to work on the Sabertooth X79 board?
Also, as mentioned, I have a single M.2 SSD on a card and moved it to the bottom slot. That is working and has my OS on it.
My board layout is as follows now;
x16 - V2
x1 - empty
x1 - empty
x16 - RTX2080
PCI - empty
x8 - SSD (OS)

I have a feeling that its down to the BIOS settings but I know little enough about them and less regarding what needs to be changed.
Hopefully something that I've mentioned stands out as glaringly obviously wrong.

Thanks

@Orbserver - see these threads, maybe you will find answer. I think x4x4x4xfails, but not sure what all Asus X79 variants that applies to
[OFFER] ASUS P9X79 DELUXE BIOS 4801 MOD NVME Dxe4 (3) << read page 2-3
[REQUEST] How to connect 2 M.2 SSDs to the same PCIe slot? (12) << See last page (also, through this thread, they explain how to find what slot is what setting in BIOS (Also thread below shows how to test and locate what is what too, I believe)
[Guide] - How to Bifurcate a PCI-E slot << See first post, how to use HWINFO to locate what slot is what setting/port in BIOS etc

@JackSted @paranoid_android - Can you guys advise, did you ever sort the x4x4x4x4 issue, or confirm which boards/configurations are affected and which are not etc

@Orbserver
I use the ASUS P9X79 pretty much same as "P9X79LE" which has no PLX chips so all slots are directly connected to CPU or PCH.
I got 2 NVME drives to work on the ASUS Hyper x16 NVME card at most, either in the any x16 slot or the bottom x8 slot. There is either an electrical or BIOS/UEFI level limitation that prevents x4x4x4x4 from working, my research on this has halted.
All more expensive single CPU ASUS boards have PLX chips to automatically switch lanes between more slots which does not work together with the bios bifurcation options at this moment except for the last x16 slot which is directly connected to the CPU but can support x4x4 bifurcation.
If you really want more (more then 2) NVME drives to work I recommend to either use additional PCIE slots with single NVME adapters or buy an NVME raid controller card that splits the lanes for you, or buy a large x16 NVME "drive".

Greetings and salutations all;

I read through the suggested threads and learned from the exhaustive research of @JackSted that getting all 4 of the M.2 SSD drives recognized is probably not going to happen... at least not by me standing of the shoulders of you giants.

That said, with two having been recognized at least and the fact that these types of drives work at all in this ancient machine will probably extend its life until PCIv4 becomes the standard and I'd have to halt all upgrades (I already hit that milestone when I maxed out the DDR3 ram at 64GB just before ASUS updated the capacity to 128GB). I took advantage of some December sales and jumped to AMD of all things (2nd Gen Threadripper with 60 some odd lanes FTW!) so hopefully this new system will last me as long if not longer than the X79. Not sure what role the X79 will play going forward. It may be underutilized (if I ever fully utilized it is up for debate) but not unused or by any means useless.

So long, and thanks for all the help... and fish. :)

@Orbserver - I "think" maybe you could possibly use three (x4x4x8)? But one of those guys would have to comment on that, not sure if anyone's tested?

I've been considering an AMD jump recently too, due to all those cores offered much cheaper than Intel's offerings lately!

Yes, thanks for all the fish

hey i got the same adapter i am having the same problem did you ever figure it out please help me its driving me crazy

I'm using the bifurcation mod on my P9X79 Deluxe board with Asus Hyper x16 v2 and two MP510 NVMe SSDs. My findings are more or less the same as what @JackSted already stated.
Both disks work with furthest from the CPU white PCIe 8x slot set at 4x4x bifurcation. However the SSD must be mounted on ports 1 and 2 on Hyper x16 board (boot disk on port 1).
Both disk also work with furthest from the CPU blue PCIe 16x slot set at 8x8x or 8x4x4x bifurcation when SSDs are mounted on ports 1 and 4 on Hyper x16. Other settings (4x4x4x4x or 4x4x8x) do not work (boot disk not found).

I also noticed a rather insignificant performance degradation using 8x slot at 4x4x. Sequential read speed (CrystalDiskMark v7 at 1MiB Q=8 T=1) dropped to 2200MB/s from 3400 MB/s on both disks.
However other sequential & random read speeds as well as write speeds were more or less the same as with single disk setups. The 16x slot did not have any performance issues at either 8x8x or 8x4x4x settings.

The bifurcated BIOS menu has some erratic behaviour. Whenever bifurcation settings are altered duplicate port link speed settings appear. E.g. if 4x4x4x4x is selected on port 3 duplicate port link speed setting row appear for 3a, 3b, 3c, 3d (altogether 8 rows instead of 4).

I also have 2 other Asus X79 boards (Rampage 4 Extreme and Rampage 4 Gene). What is the procedure to add bifurcation support for these boards? They are already running NVMe support & latest uCodes.

Hi guys, Please if im directive my self incorrectly ido to my ignorance, its the 1st time i have joined a forum. i have a friend that has a system like mine i7-3970X 64GB RAm, Sabertooth X79 MB, nVidea Geforece GTX 780, i hav 2 satas ssds (damsung 840 1TB , Intel ssd 465 GB), 2x WD Green 3TB. I was hoping to move all this drives to another computer as my friend in south america told me he got an asus asus hyper m.2 x16 card with 4x ADATA XPG SX8200 Pro NVMe sdd 2 TB (to fit in the card). I have the 780 video card on the first PCIe x 3.0 16x(slot 1) and on the 2nd PCIe 3.0 16x (slot 4), the last slot 6 is PCIe 3.0 16x(but is only 8x- manufucturing). I hope this details are sufficient and ok if not i can share what ever details you need.

What i did so far was:
1. download "SABERX79 (4801 bifurcation)"
2. format pen drive with fat32
3. put "SABERX79 (4801 bifurcation)" on root directory
4. put it in back usb socket with "white"marking and pressed the little button en hold it. - is flashed blue then did speed up and when it turned off i took pen drive out.
5. unplug pc and inserted PCIe adapter card with 4 ssds
6. booted cmos: showed: 1. they uefi setting on the samsung ssd for windows 10 boot was not there any more. went into boot and put cms setting as instructed. also show the nvme as 'pata ss:'

windows 10 detects only 1 of the ssd but not the other, i took 1 out and the same. the idea was to have it all as a raid 0.

Im at my wits end, have spent close to 22 1/2 hours on this since i got the parts. maybe its a little stuped thing im doing, i have read that many other have got this up and running.
im thinking of unplugging all dirves and boot from windows 10 dvd and format the ssd like but i can only get 1 to be seen in windows.
n.b. i saw a video on youtube about 2 weeks ago that (cant find it now) that they went into system manager and added other drivers for each of the ssds and i think for the nvme driver under storage but thats hard to remember.
IF im not being a serious pain, please could do with help. I think i have read and re read x3 all the posts here and im still wondering if I am the doing something wrong.
Again if i places this post incorrectly plese do forgive me.
Thank you

Hi guys I think i have found what might be the problem with my system. if i put the "asus hyper m.2 x16 pcie 3.0 x4 expansion card" with the 4x "adata xpg sx8200 pro m.2 nvme ssd 2tb" in the 1st physical PCIe x16 slot, the bios has it as 8x (i get to seed 2 of the ssds), if put it in the 2nd PCIe 16x slot it showes 1, and the last PCIe slot is physical 16x but has only got pins for 8x. i wonder if for some reason i could get the bios done with reversed slots PCIe 1st and last. i might be able to get all four ssds. or is there another bios version for the asus sabertooth x79 that does that. again i hope i havent placed this post in the wrong section.
Thankyou