[Guide] - How to Bifurcate a PCI-E slot

Nothing Fancy in the slightest, I’m not looking to use them in a RAID it was purely for the good old my car is faster than your car test :smiley: 5GB/s is a good speed.

Windows -> Disk Management -> New Stripped Volume -> Then added the two drives



Well you did it the correct way. I was using MS Storage Spaces and I got to say the performance is subpar and it doesn’t stripe the data across two disks.

Just recreated my array in disk management and the AS SSD benchmark doubled. Thanks for the tip.

So anyone interested DO NOT USE STORAGE SPACES!!!

The RU steps are just to test the settings before flashing, right?

Not having any luck enabling bifurcation on a Supermicro X9DRi-F. The settings are already visible in the BIOS, but I went and followed the instructions to edit the optimal/failsafe settings in the BIOS, as well as the other timeout options you were talking about. I can only see the first SSD in an ASUS Hyper M2 card (of 3). It’s in a 16x slot that’s set to 4x4x4x4, both visibly in the BIOS and in the edits I made before reflashing it.

Bizarrely enough, forcing some of the options that Supermicro has limited to “UEFI Only” or “Legacy Only” to “UEFI First” (option not normally visible) before re-flashing made the nice LSI EFI utility show up in my Setup menu. I guess it wasn’t a complete waste.



If you want to use Tiered Storage on Windows you have to use it AFAIK, There is a really cool trick to getting it working on Windows 10 (You can’t create a Tiered on Win10 but you can access and use it on Win10). Create a Win2012R2 USB using Rufus boot from it, load up enable Storage Spaces create your multi tiered storage. A-NVMe SSD B-AHCI SSD C-HDD. Then shutdown boot into Windows 10 and access your Tiered Volume. Magic.



Yeah you don’t have to Flash your BIOS you can just use the RU utility if you’re worried about bricking your mobo. With the RU utility, you just have to edit the HEX codes according to the available settings.

Might be different for you but on mine (If I remember right): FF was auto, 00 was x4x4x4x4, 01 was x4x4x8, 02 was x8x4x4 etc… you get the picture. It might be different depending on your Mobo, but as this is an Intel thing rather than motherboard specific thing it might be the same.



Yeah you don’t have to Flash your BIOS you can just use the RU utility if you’re worried about bricking your mobo. With the RU utility, you just have to edit the HEX codes according to the available settings.

Might be different for you but on mine (If I remember right): FF was auto, 00 was x4x4x4x4, 01 was x4x4x8, 02 was x8x4x4 etc… you get the picture. It might be different depending on your Mobo, but as this is an Intel thing rather than motherboard specific thing it might be the same.




Huh. I went all in and edited the BIOS. It was already showing options to bifurcate all of the slots, I tried 4x4x4x4 to no avail, I can only get the 1st and 4th slots in the M.2 adapter working. I tried 4x4 in an 8x slot (with a 1x card plugged in) and it completely disappeared. Me thinks the board itself can’t actually handle it properly?

I changed the Failsafe/Optimal settings to 4x4x4x4 for the desired slot, saved the ROM, flashed it using AFUWIN (I know, I know). The change definitely went through, cleared the CMOS after I flashed it, it showed the edits I made to some of the other settings. No change in behavior though.

Anybody was able to activate that on the Asus Rampage V extreme?

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Could anyone help to see I have asrock E3C226D2I and empty pcie x16 mode in the bios has no function to change to x4x4x4x4 I can see only one drive with Asus Hyper M.2 x16. Is this method work with my motherboard this machine run Freenas system thanks for your help.
https://www.asrockrack.com/general/produ…226D2I#Download

Hello!
My system is currently:
MB: ASUS P9X79 DELUXE BIOS 4801 MOD, CPU: Intel Core i7-3930K 3.2 GHz, Memory: DDR3 PC12800 32 GB, Disk Drives: Intel 520 SSDSC2CW120A310, 2 x Seagate 3 TB, Graphics: QUADRO K5000, OS: Win7 x64

After installing the expansion card, I want to change to WIN 10 Pro x64.
I decided and programmed BIOS from my motherboard P9X79 Deluxe, firmware from TumKo. Thank you for the work done.
After programming, I reset all BIOS settings.
In the operating mode, SATA set the AHCI mode, since it saw that it was not recommended to install RAID. Four 256 Gb disks (MZVLW256HEHP-0000) are installed through the adapter into the first PCIe slot (closer to the processor). The Dell Ultra-Speed ​​Drive Quad PCIe NVMe M.2 SSD x16 Card Up to 4TB Capacity 9GB / s (DP / N 06N9RH) adapter itself. When you turn on the computer to install Windows, the installer identified one of the four disks installed in the adapter. I installed Windows Pro x64 on it. Standart NVM Express Controller was defined in the system; one disk SSD was visible in disk devices. Installed the driver Samsung NVM Express Controller. The disk in the system was left alone. In computer management, in the disk management section, one disk is visible.
I understood the problem of inoperability.
The board that I have, so to speak, is an adapter for m.2 for connecting to a PCIe slot.
In order for the motherboard to see all SSD disks through the adapter, you need the support of "Bifurcation Control". As written in your topic. It turns out I need to change the BIOS. That would be setting up the separation of PCIe x16 in x4x4x4x4 mode. After such a separation, all four disks should be defined in the system, with which you can then do anything.
If anyone can help with the channelization of one PCIe slot for an adapter card with four disks, I will be very grateful and grateful.
The Asus hyper m.2 adapter works and performs the same function, and the same separation feature is also required for its operation.
I have never been involved in programming, and I can’t understand much of what you are discussing here. How can this be done for the P9X79 Deluxe motherboard, I think it will come in handy for many and will help in solving a similar problem.
Please help with the BIOS file with Bifurcation support in the desired mode.
Thank you for your help!

Did You solve your Problem? I am at your problem point as well -.-

@alex_tech - I made you NVME Mod BIOS with Bifurcation settings visible here - [OFFER] ASUS P9X79 DELUXE BIOS 4801 MOD NVME Dxe4 (2)
RAID mode may or may not be required I am not sure, but the x4x4x4x4 would need to be set.

@Powersliver - see link above for mod BIOS, flash via USB Flashback, then see this guide for how to install OS (see post #4 of the “This is what you should do” section here)

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Hello!
Thanks for the answer @Lost_N_BIOS. Since this topic was not answered immediately, I wrote in another topic. [OFFER] ASUS P9X79 DELUXE BIOS 4801 MOD NVME Dxe4 (3) In it you helped me make a version of BIOS. In that topic, I wrote a result with screenshots and asked for further help. But it’s evident that this is off topic, no one answered me anymore.
@Powersliver - all my experiments, you can read the conclusions in that topic. [OFFER] ASUS P9X79 DELUXE BIOS 4801 MOD NVME Dxe4 (3)

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Ohh, I see what happened, thanks for clearing that up! I wondered what was going on when I replied earlier, but didn’t notice that when I looked (sleep at the wheel )
Surely they will help, those guys all know about doing what you want to do, maybe they didn’t understand what you needed help with. Sorry I can’t help with settings, I don’t have NVME nor have ever used

The method explained in the posts above should work for most motherboards ( Depending on how the Mobo Manufacture configured the board and how it’s slots are wired up, your mileage may vary slot to slot. As you can see in one of my previous posts one of my slots was preBifricated so I was unable to go further. If you have onboard m.2 slots that share PCIe bandwidth this may also cause issues as well.
Check the number of lanes your CPU has available and that they are correctly wired.

The guide is correct but a little confusing.

Please READ the guide more than once BEFORE you attempt it.
Download all the tools first and get a pen and paper out and write down the Hex numbers you need to remember.

I am just getting started here. Before I really get educated on all the tools and processes a simple question. My motivation are GPUs per motherboard. I run a system with 17 1080 Ti’s at the moment, connected to a 11 slot Supermicro X9DRX+ using two 1-to-4 PLX based riser cards.

Splitting the ten x8 slots to clean x4x4 using bitfurcation would be really interesting and hopefully also more stable than working with my current setup. How are the chances my motherboard will support this and do the RSC-R2UU-2E4R 2U PCIE 8X to 4X4X adapter work with GPUs and how do they deliver twice the PCIe slot power to the cards?

cannot believe it. success by one shot. Thank you!!
now the question is, how do I dump my current bios and flash it?

OK, I just got hold of an ASrock Ultra Quad card, the one with 4 M.2 slots requiring x4x4x4x4 bifurcation to work in an x16 PCI-e slot.
The mainboard is an Asus X99-E-10G WS and the CPU is the ridiculous Core i7-6950X that I got after it was tested/reviewed where I work. Anyway, so if all is well I have 48 lanes available for use.
I’m assuming I can’t set bifurcation on this ASUS BIOS, not even while it is a workstation board. Ridiculous.
So I bumped into this thread.

Any insight on how to best put the Ultra Quad M.2 card to work? Do I have to hexedit the BIOS firmware? Does the RU tool work for this bios?

@afluisterland , I can only tell from experience with X79 and C602 Systems. Bitfurcation settings heve been enabled on the C602 Boises right from the beginning while in X79 there were hidden.
That tells me that the ‘large’ chipsets have bee capable of supporting this feature at least since 2011/12.
That it had been deactivated or hidden on more consumer related versions like the X79 chipset was probalbly due to stratetic reasons.
Anyway, because of my experience with X79/C602 systems, I think that the bitfurcation settings are present on X99 Bioses as well, but hidden.
So Bios images of X99 boards have to be modified. But in general the bitfurcation feature should be available on those systems.


Ah, thanks, sounds good. Just for clarity, this is the board’s block-diagram; https://youtu.be/sOjhToEk_GE?t=355
I will use the guide here and let y’all know how it turns out. It’s a bit of a gamble due to the PCI lane extenders. Not sure how it interacts with BIOS.

Ah, okay, on my X79E-WS, the single ×8 Root Port is directly connected to a ×16(×8 elecrical) onboard slot.
That one could be bitfurated without any problems, I think.

If your board has all the Root Ports connected to the PLX chips, then it might get troublesome.
Easiest try should be to bitfurcate slot PCIe1. But that is where your graphics card is connected…?
They used the single ×8 Root Port to provide lanes for the M.2 and U.2 slot, as well as for the two 10GbE connectors.
(The M2. and U.2 connector share 4 lanes, maybe only one connector can be used at a time?).

But this is all guessing around, I have no certain clue how bitfurcation would affect your system.
Mabe trying out PCIE 5 or 7 first would make sense, but PCIE 4 and 6 shoud not be populated at all.
Safest try would be something like unpopulating slots PCIE 4, 5 and 6 and using the UltraQuad Card on slot PCIe7.
The according Root Port (#2 or #3?) which provides for Slots 4 through 7 must be set to ×4×4×4×4, if the hidden option supports this setting at all.