@Lost_N_BIOS :
I re flashed the mobo bios, loaded optimized defaults and then re flashed vBIOS of the card and I am very happy to say that x16 is now enabled permanently except that 3.0 is enabled when the card is under stress only. In normal condition is x16 1.1. So I call it success.
@hancor :
As I said before I bought a 4K monitor. I was referring to the capabilities of the card up to 8K which means that the card’s hardware supports it. Never thought of buying an 8K monitor. Anyway everything is smooth now.
Thank you both for your help my friends. Nothing would have been accomplished without your valuable help.
You’re welcome, and it’s great you finally got this fixed again @montegonexus 
- the PCIE 3.0 and 1.1 is normal expected operation of the AMD Drivers, it’s power saving feature (actual GPU clocks often go down too, but not always, see this in the sensors tab)
See, here is mine, and under load it goes up to x16 3.0 and clock speed go back to regular max speeds too
So, x16 again, and you did get OS installed via secure boot now too, correct?
Delighted to hear you are out of the NVMe SSD and UEFI "deep dark woods"!
As Lost_N_Bios noted graphics cards routinely stop down the speed and go into power saving mode; when not being driven hard.
Here’s mine in "Afternoon Nap mode"
Okay now you can earn some extra drachmae and buy a cool graphics card with 8K monitor!
Take your wife out on a date first though; it provides for better long term happiness…you know the drill.
Cheers and did you find the OUZO? We may have to hoist a drink to your final SUCCESS…
@Lost_N_BIOS :
Yes I have installed win 10 Pro properly.
@hancor :
Really can’t describe how happy I feel now that everything worked well. As for the Ouzo drink it’s not my favorite and in general I have been a social drinker since 1996, meaning that I will drink one or two drinks once or twice a year. Sometimes these drinks are consumed in a 5 years time. I used to consume a lot of whiskey on a daily basis back then but I decided to keep a distance since and stay clean.
Thanks again. You are awesome my friends.
@Lost_N_BIOS :
@hancor :
UPDATE!!!
I have decided to buy a new graphics card and I bought the Asrock Radeon RX 560 2GB Phantom Gaming (90-GA0400-00UANF). I have the same problem with the x8.0 bus speed. I have tried BIOS reset and new drivers but it does not go to x16. Any suggestions? Thank you.
The problem is on the specification page, which you will find here:
https://www.asrock.com/Graphics-Card/AMD…/#Specification
Bus Standard - PCI Express x16 Gen3 (uses x8)
In contrast, the 580 I recommended some time ago uses the full x16 PCIe specification, see here:
PG D RADEON RX580 4G OC
https://www.asrock.com/Graphics-Card/AMD…/#Specification
Bus Standard - PCI Express x16 Gen3
Do yourself a favour and return it, for an appropriate upgrade… Less muss and no fuss.
The price differential should be fairly minimal…
Cheers
Asrock makes graphics cards? 
You could still take the 560 back for refund, wait 6 months and you can be almost be assured the price will drop significantly as AMD is releasing their Navi cards which should drive the pricing on the 580 further down.
In any case an option…
Cheers
I can’t download this bios file. Can you put it up again ? Asus P9x79 (BIOS modded for NVMe SSD booting)
Thanks
I would like the modded P9X79 BIOS 4801 dated 2014/07/28. That is the last Asus P9X79 bios released. All I need is updated for NVMe SSD booting. But, other updates are ok.
Thank You
looks like the file was posted in #2
https://www.asus.com/us/Motherboards/P9X…pDesk_Download/
@chuckbam - the BIOS at post #2 on page one of this thread is still there, attached at bottom of his post and it’s hosted by this site so download still works fine and I checked to confirm it too.
Why do I get the message "Zurück zur Forum Übersicht " ?
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Sorry, it works in Firefox. got it Thank You
@chuckbam - That means “Back to Forum Overview”, not sure why you would be redirected like that, maybe some glitch with the browser you were using and this site?
Glad you were able to download finally 
I was going to download it and re-upload it for you if you couldn’t get it, but I wasn’t sure if you maybe just didn’t see that attached file link or not 
Hi I have flashed this BIOS, but it didn’t find my NVMe I have
adapter:
https://www.asus.com/fi/Motherboard-Acce…-2-X16-CARD-V2/
and hardisk :
https://www.samsung.com/us/computing/mem…tb-mz-v7e1t0bw/
mobo is Asus P9X79
And windows 10 installation works perfect but BIOS doesn’t find hardisk.
When I try to boot to Win10, computer says "check CSM parameters". My CSM setting is "disabled", as directed.
What could be wrong?
I flashed the Bios with the mod and my Intel 600p NVMe drive shows up in the bios and boots ! I have a hyper m.2 x4 card. Could I use the hyper m.2 x 16 ? Would I need a Bifurcation Mod ?
@chuckbam - yes, you need this BIOS - http://s000.tinyupload.com/?file_id=22813479928448371943
Flash via USB Flahback
Thanks a bunch. I looked and see the Bios P9X79.CAP. But what is the P9X79.md5 ?
That is checksum file, so you could check MD5 checksum to be sure file you downloaded is OK, nothing needed for flashing, I’m sure it’s fine