@d4nt3ch - see above post by agentx007 - you may get lucky with USB 3.0, but I can’t remember anyone having success with that, including you’ve been properly trying to USB Flashback a ROM BIOS and it’s failing, so must be the USB stick.
LED remaining on seems to be the key indicator here, and no increasing LED flicker as it nears the end. Check your drawers in desk, old boxes in attic, neighbors, friends etc. There is old, tiny and forgotten, USB 2.0 sticks laying around everywhere 
LOL I was just renaming rom files to cap. I’ll use the converter and a USB 2.0 and will report back.
If only it was THAT easy 
@d4nt3ch - You can still try your old rom BIOS with flashback, just name it to the proper USB Flashback name for those BIOS (SABERX79.ROM) and try again with your current USB (formatted to 1GB for best chance of success)
If you get it working, then use the converter BIOS and do it again, then you’ll be on the CAP format BIOS - which in reality is also still just ROM/BIN BIOS, the capsule is removed/stripped before image is written to the flash chip.
Actually, the increasing flicker did happen but then solid blue after. The sabertooth manual mentions nothing of this so thank you to all that are informing me properly 
Well that is a good sign, but agentx007 said it should go out at end. So maybe you are almost there. Try more with the rom BIOS named as I mentioned above, or use that converter BIOS
I dunno why i said i was on bios 1709 LOL i meant 4701. I was on Bios 4701 before this brick, and before that I was on the 4801 beta bios, which means I am already on the CAP format for my bios.
I did try flashing ROM bios, solid blue didn’t even wanna blink.
I tried using a USB 2.0 flash drive although it’s one of those SD card to USB flash drive sticks (you put a micro SD card in it) but it is 2.0 by specification, I tried flashbacking 4701 (renamed to SABERX79.CAP) and still, blinky blinky for a minute, solid blue after.
The USB stick I tried using this time is a IOGEAR GFR204SD.
Is it still the stick?
And i partitioned it to 1gb, FAT32
Wow! So, flash 4701 stock and then be done, at least until you get sorted out I mean. How did you brick the BIOS if you can’t flash the BIOS? 
IOGEAR - GFR204SD is a card reader, not a a USB Stick - https://www.iogear.com/product/GFR204SD/
SD card in a USB adapter will not work for this. You need a normal, regular, USB Thumb drive
Okay I shall buy one today and will report back.
I bricked my bios because I attempted to flash the modded nvme bios using one of my 3.0 sticks.
I tried reflashing 4709, no luck! Blinky Blinky, solid blue 
I expected a failed Flashback would = no flash happening, so that is what I meant by how did it brick. Seems like maybe it did some of the process, and stopped mid-way through or something?
Yes, get some cheap small USB 2.0 stick, and then stop at a friends and borrow two more, sometimes you’ve got to try 10 before you find the golden goose 
@d4nt3ch
Generally USB Flashback is not like “playing game”, if you don’t know how to do it.
First of all which bios you were trying to flash via flashback? from which post? number?
Your bios needs .CAP bios files as you already have 4701 version.
Or maybe .ROM if you didnt change it.
You will have to answer us if your bios takes .ROM or .CAP files, but i believe it takes .CAP files.
The bellow is for .CAP only.
If you have .ROM just swap .CAP with .ROM.
To flash bios (.CAP) file you need USB 2.0 formated as fat32 and not above 2gb.
So lets take it from the beginning:
1)Take the bios you want from the post you are interesting in.
2)Rename that bios to “SABERX79.CAP”, and NOT “SABERX79.CAP.CAP”, Please select in windows to show file extensions.
3)Clean everything from usb pendrive.
4)Copy SABERX79.CAP file into your’s usb2.0 pendrive.
5)Turn OFF your pc.
6)Take this usb from any port you had it and insert it in white usb port(down from the flashback button).
7)Just press the flashback button for 5 sec and wait the proccess to start.
8)Wait until it stop blinking and thats it.
If that doesnt work then disconnect your cpu, ram, gpu from motherboard and repeat the above steps (only steps 7 and 8).
(Please if you dont know how to disconnect the above dont do it alone, unless you will harm your pc).
Let me know if your problem solved.
Could someone explain how to do step 1?
In general I’m not 100% certain I managed to flash BIOS. The flashing goes slow then fast, then off … so looks like it worked, but what should I have in the BIOS info? I’ve followed all the advice here(used an old, 2GB usb 2.0 flash drive)
version 4801
I have:
build date 07/25/2014
EC Version MBEC-X79-0606
ME Version 8.1.51.1471
The disk still shows up in BIOS as PATA SS. Are there any other settings in BIOS/system I should do with the disk (it’s a Kingston A2000 500 GB and W10 as a secondery drive doesn’t have any problems with it).
Thanks!
Unplug ALL other hard drives and SSDs (other than that NVMe), and then install Windows on NVMe (remember to boot it in "(U)EFI"mode). When that’s done, you should get standard options in Windows installer (along with GPT and booting partition (assuming you didn’t partition the driver earlier).
If I format that drive in windows before installation (clean install from a USB installation drive) I get this error:
"Windows cannot be installed to this disk. The selected disk is of the GPT partition style.
Windows cannot be installed to this disk. This computer’s hardware may not support booting to this disk. Ensure that the disk’s controller is enabled in the computer’s BIOS menu."
If I delete the partition I get this error:
"Windows cannot be installed to this disk. This computer’s hardware may not support booting to this disk. Ensure that the disk’s controller is enabled in the computer’s BIOS menu"
So I’m unsure if A) I missed some important settings in BIOS B) I didn’t flash the BIOS properly.
Is the BIOS info I provided correct?
Make your USB GPT then put install media on it. Then install to RAW disk and let windows set it up
I’ll try that, but would you be able to confirm that those numbers I provided (BIOS build data, versions ) are correct? I’ve been trying to figure this out for the last two days by my self and I’m starting to think I must be missing something really simple here.
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Well … I’ll be damned … this worked!! I would have never thought that I need to set a different format for the install USB drive. Thanks!
@kindalost - None of that matters, if you are using some NVME Mod BIOS from here, only linking to that post or giving the post # will help us to tell you if BIOS is OK to use or not. I think I removed all buggy ones for 4701
Here is latest with bifrucation mod and all updates tested and all good now #173 - [OFFER] ASUS Sabertooth X79 4801 beta BIOS (compl. updated incl. NVMe support [v4]) (12)
And here is one with microcode and NVME mod only #147 - [OFFER] ASUS Sabertooth X79 4801 beta BIOS (compl. updated incl. NVMe support [v4]) (10)
* Ahh, you got it, nice! You were replying while I gathered the above reply/info for you 
Yes, you have to install from GPT >> To >> GPT or RAW
@Lost_N_BIOS - Downloaded the BIOS from #173 a few days ago but wasn’t able to update until now… Everything seems fine now, no performance penalties ;). Once again a big THANK YOU to you and all involved.
hey Guys, got some trouble with using my new Samsung Pro970. PCIe Adapter: https://www.amazon.de/dp/B07RZZ3TJG?ref_…_302_E_DDE_dt_1
sticks like in every other case in second PCIe x16 slot. Installed today nearly every Bios version that has been posted in this thread and
Configured bios in CSM/SATA and everything that has been promoted.
It’s still not shown as bootable option or something and i dont know what i can do else. The leds on M2-ssd blink up once if bios gets loaded up. Thats the only sign i get to realize it gets somehow electrical signal.
Otherwise i removed external Sound-card and disconnected every normal SATA-port to refuse that any ports are parallel wired and disconnecting each other while engine.
Bios updated worked also, Bios Versions changed, (tried those A/B/C bios-setups (D is open, since not released yet)) the only point that did not show up was under “advanced options” → Guess that there should be created NvmE Options/support or something, thought i have seen an image of someone but didn’t find now as prove.
I hope that i just forgot any point. Thanks for reading.
#edit i think i just bought false adapter, going for new one…