Hi everyone,
 
Brand new Asus Strix motherboard (B360-F Gaming latest BIOS) reads my GTX670 at PCIe x16@1.1 instead 3.0 (yes  with render running) and I never had such problems in an older Gigabyte motherboard.
 
During first boot it said:
The VGA card is not supported by UEFI driver.
CSM (Compatibility Support Module) settings have been changed for better compatibility.
 
-Is the pciex speed lanes correlated with UEFI support?
-If so, where can I get a vbios update for this? 
 
I already did a fresh OS install, messed w/ all bios settings (pciex16 speed gen1 2 3, auto) nvme mode settings, loaded defaults, messed w/ windows power management for PCI-ex (savings /off) and so on. Removed the card from slot and checked/cleaned everything, re-seated, system works fine and there is no signal of damage on the connectors in either mb and vga, everything looks brand-new.

As you can see below it boots in either 3.0 or 1.1 pciex mode -completely random- and it doesn't change, if it boots on 1.1 its staying there no matter what you do, until you restard and get lucky maybe..
 
 

 
edit by Cool GTX tried to embed the photos
 
 
 

Welcome to the EVGA Forums
 
1) Depends on what CPU & other Hardware is in your MB & what slot the GPU is in
 
I'd test with GPU-Z
 
 
 
Remember to turn Windows 10 Fast Startup OFF, when upgrading drivers, firmware or hardware

[It does this by putting the PC into hibernation instead of "fully shutting down."]


Windows Central - How to disable Windows 10 fast startup (and why you'd want to)

How-to Geek The Pros and Cons of Windows 10’s “Fast Startup” Mode
 

Cool GTX
Welcome to the EVGA Forums
 
1) Depends on what CPU & other Hardware is in your MB & what slot the GPU is in
 
I'd test with GPU-Z
 
 
 
Remember to turn Windows 10 Fast Startup OFF, when upgrading drivers, firmware or hardware

[It does this by putting the PC into hibernation instead of "fully shutting down."]


Windows Central - How-to Geek
 

Hi Cool GTX, thanks for the prompt reply! 
 
I did disable fast startup, everything is at performance mode including bios;windows. GPUZ screens attached in the first post.
 
Sorry I guess i didn't explained it properly, I just have one nvme m.2 installed (pciex 4x) and the video card is at pciex16_1 (slot 1) on the first slot that it supposed to be for max link speed.
 
The motherboard sets video card to 1.1 (2.5GT/s) mode instead 3.0 (8.0GT/s)>RANDOMLY.
 
Cold start usually comes at 3.0 (OK) and if restarted, returns to 1.1. But again this is totally random.
 
When it is at 1.1 mode it will never scale up to 3.0, no matter if rendering or playing games, this is not a power saving feature as I changed and messed with it all in both Windows and BIOS and monitored it. Looks more like a bug due sometimes booting in 3.0 correct mode, so not hardware limitation either.
 
The video card is old and does not have UEFI support, has to launch in CSM. But it always worked at 3.0 in my previous system and I also tested in brother’s PC to guarantee. On those systems it recognizes at 3.0 without issues even after restarting many times so I know it’s not a video card issue and indeed this new Strix B360-F motherboard that is causing it.
 
So I want to know if not having UEFI support is making the motherboard set it down to 1.1 thinking its "super old card" (cof cof), but still doesn't explain why sometimes it boots at 3.0 mode.
I want to update the vbios to UEFI and test to discover if motherboard is faulty or not as it is brand-new and I could warranty.
 
This is all my troubleshooting steps:
Performed fresh OS install, checked all bios settings (pciex speed gen1 2 3, auto) nvme modes settings, loaded defaults, disabled secure boot, fast boot etc. Cleared cmos, changed windows power management for PCI-ex (savings /off /performance mode) disabled fast startup . Removed card from slot and checked/cleaned, re-seated, system works fine and there is no signal of damage in either pci lanes on the mb and video card, everything looks brand-new.
 

Cool GTX
When running GPU-Z
 
click the "?" next to the PCIe version ... then select "Start Render Test"
 
I'd set the PCIe slot to 3.0

Here you go, as I said it doesn't change if boots in 1.1 mode, BIOS settings were changed to PCIEX16 Gen3 and issue persists.
 
How can I update this videocard bios to UEFI to test?

jonkrmr
Have you tried forcing PCIe speed to 3.0 in the BIOS of your motherboard?

I did set PCIEx16 to GEN3 inside BIOS, issue persists. No matter what setting, auto, gen 3 gen 2, it randomly boots in either 1.1 or 3.0...
 

Perfect! I will try to get it and see how it goes, thank you!

I got the new UEFI firmware from support, installed but unfortunately the issue persists.
 
I have created this album at imgur sharing all screens from bios settings to windows and my computer setup: imgur.com/a/oKzQ2pE
 
At this point I have tried everything I could find online, if you guys have any other ideas let me know but I am 99% sure the motherboard is faulty somehow.