Question System unstable when PCIe x16 is set to either Auto or Gen 4, forcing it to Gen 3 is the only way to get stability ?

[iscottjs]

Hi all,

I've just finished this new build (RTX 4070 Ti, ASRock B650M, 7800X3D) and everything has gone smoothly except this last issue when installing the graphics card.

Everything was running stable until I connected the GPU and tried to install the drivers. The system boots into Windows just fine for the first time when the display is connected to the GPU but while the Nvidia drivers are installing the system becomes unstable. The system hard resets during driver installation and continues to power cycle after that.

It sometimes does manage to boot into Windows but after 30 seconds on the desktop it will lock up and reset.

After doing some research, I've found many people with similar issues here and here and here. I don't see many people using my specific motherboard though.

It was this thread that had the most information that allowed me get the system running stable, noted below.

What I've changed that has worked (currently stable):

• Force PCIe x16 link speed in the bios to Gen 3 instead of Auto or Gen 4.
• Setting "Power management mode" to "Prefer maximum performance" in the Nvidia control panel.
• Uninstalling and reinstalling drivers in safe mode using DDU.

Since making these changes, the system is so far running stable and I'm able to run MSFS in VR and 3DMark without any issues for long gaming periods.

What I've tried that didn't make a difference (when in PCIe Gen 4 or Auto mode):

• Re-seating the GPU and memory, multiple times.
• Re-installing Windows, multiple times.
• Using 2x PCIe cables from the PSU instead of sharing a single cable (as per instructions).
• Flashing motherboard bios (was on 1.28, now on 2.02).
• Upgrading or downgrading Nvidia drivers (tried the latest 546.33 and the older 537.xx drivers, using DDU).
• Tried different cables, ports (HDMI and DisplayPort) and different monitors.
• Disconnecting non-essential components, e.g. WiFi adapter, games controllers, etc.
• Monitoring all temperatures (they're all fine).
• Resetting CMOS.

Notes about my setup:

• GPU is installed in the top slot (PCIE1).
• Samsung 2TB M.2 NVMe PCIe 4.0 drive is installed in the primary M.2 slot with heatsink (M.2_1).
• GPU is connected using the supplied Y-splitter and two separate PCIe cables from the PSU.
• All chipset drivers and other motherboard drivers are installed and up to date.

Setup diagram:

https://imgur.com/a/foW1kG9

View: https://imgur.com/a/foW1kG9


Photo of BIOS:

https://imgur.com/a/XGVAMtd

View: https://imgur.com/a/XGVAMtd


Questions:

1. I realise there's not much tangible difference between Gen 3 and Gen 4, but should I be worried that this workaround is hiding more serious hardware/software/compatibility issues that I shouldn't ignore and might bite me later? It's a lot of money to spend on something that might not be quite right.
2. Would this be a motherboard or GPU issue or something else? I'm not sure who to contact for support.
3. I'm no expert with modern PCIe, but could the M.2 NVMe drive be taking resource priority away from the GPU and causing it to crash? Any useful bios settings that might help?
4. Is this just a software issue? Could this issue fix itself as new software/firmware/drivers are released?
5. Anything else I should try?

What I find interesting is that the machine will run stable even in Gen 4 when changing it from Gen 3 and restarting, but I will only get one stable session out of it, if the machine is powered off/on while still set to Gen 4 mode then it won't boot again until I change it back to Gen 3 and restart. I'm not sure how relevant that is but it seems strange.

Any help is appreciated, if this is normal and I just need to use Gen 3 going forward then fine, but I don't like the idea of keeping potentially faulty or incompatible hardware for the lifespan of this machine.

I do actually have a spare unboxed ASRock Pro RS motherboard (odered 2x by mistake) that I need to return to Amazon, I'm tempted to swap the motherboard but don't want to go throug hthe hassle if it's not a motherboard issue, and I may not be able to return it once opened if there's nothing wrong with it in the end.

I'm not sure what else to try or who to contact for support if I need to return some hardware.

Thanks,
Scott.

PC Spec:

• AMD Ryzen 7800X3D
• ASRock B650M Pro RS Micro ATX AM5 Motherboard
• Corsair Vengeance 32 GB (2 x 16 GB) DDR5-6000 CL30 Memory
• Samsung 980 Pro 2 TB M.2 PCIe 4.0 X4 NVME
• Asus TUF GAMING OC GeForce RTX 4070 Ti 12 GB
• Corsair RM850x (2021) 850W
• Windows 11 Home

 

[iscottjs]

Hey all,

A few days ago I posted this thread where I seem to be having boot issues when the PCIe x16 link speed is set to Auto or Gen 4 in the bios, but forcing it to Gen 3 seems to be working fine. I've still not found a solution, but I've decided to leave it at that setting for now and see how it goes.

However, after some more digging around in the BIOS, I noticed that I only have these lane configuration options:

• Auto
• x8x8
• x8x4x4
• x4x4x4x4

With this set up, I was expecting to see an option to set x16 as in this screen shot (taken from internet):

https://imgur.com/a/auht0Id

View: https://imgur.com/a/auht0Id


These are the options that I see in my BIOS currently:

https://imgur.com/a/FDlyeNd

View: https://imgur.com/a/FDlyeNd


My setup:

https://imgur.com/a/foW1kG9

View: https://imgur.com/a/foW1kG9


Is this normal/expected? What could be causing the x16 option to not be available?

All graphics and motherboard drivers are up to date. Motherboard BIOS is on the current latest version, was originally on 1.28, now on 2.02.

Thanks,
Scott.

PC Spec:

• AMD Ryzen 7800X3D
• ASRock B650M Pro RS Micro ATX AM5 Motherboard
• Corsair Vengeance 32 GB (2 x 16 GB) DDR5-6000 CL30 Memory
• Samsung 980 Pro 2 TB M.2 PCIe 4.0 X4 NVME
• Asus TUF GAMING OC GeForce RTX 4070 Ti 12 GB
• Corsair RM850x (2021) 850W
• Windows 11 Home

 

[boju]

Are you using a riser cable for the graphics card to orientate it differently or is the graphics card connected directly to motherboard? If former, these riser cables can cause issues like that, reason im thinking of it because lack of 16x is weird.

 

[Aeacus]

Is this normal/expected? What could be causing the x16 option to not be available?

Contact AsRock since the BIOS you have, is cookie cutter BIOS and not specifically made for your MoBo.

This is evident by the PCI-E configuration of x4x4x4x4 but your MoBo has only two PCI-E slots, and not 4.
That, and based on MoBo specs, 2nd PCI-E x16 slot can run only in x4 mode. So, the x8x8 you see in BIOS isn't possible either.
MoBo specs: https://www.asrock.com/MB/AMD/B650M Pro RS/index.asp#Specification

 

[iscottjs]

Are you using a riser cable for the graphics card to orientate it differently or is the graphics card connected directly to motherboard? If former, these riser cables can cause issues like that, reason im thinking of it because lack of 16x is weird.

Not using a riser unfortunately, GPU is connected directly to the motherboard.

 

[iscottjs]

Contact AsRock since the BIOS you have, is cookie cutter BIOS and not specifically made for your MoBo.

This is evident by the PCI-E configuration of x4x4x4x4 but your MoBo has only two PCI-E slots, and not 4.
That, and based on MoBo specs, 2nd PCI-E x16 slot can run only in x4 mode. So, the x8x8 you see in BIOS isn't possible either.
MoBo specs: https://www.asrock.com/MB/AMD/B650M Pro RS/index.asp#Specification

Thanks, that's an interesting point. I've already contacted them about this now. So are you saying that Asrock simply haven't made any BIOS available for this specific motherboard and everything on their support site is just cookie cutter?

 

[Aeacus]

So are you saying that Asrock simply haven't made any BIOS available for this specific motherboard and everything on their support site is just cookie cutter?

It is evident that the BIOS used on your MoBo is for another MoBo, most likely ATX MoBo with 4 PCI-E slots.

As of other info on MoBo support page - that is hard to tell.

Did look holy bible of PCs (your MoBo manual) and it is filled with typos;
Page 5:
"BIOS Feature - AMI UEFI Legal BIOS with GUI support"

It should be "Legacy" not "Legal".

Page 7:
"24 - ddressable LED Header (ADDR_LED1)"
"25 - ddressable LED Header (ADDR_LED2)"

It should be "Adressable" and not "ddressable".

There could be more typos but i didn't look that in-depth. I was more interested what holy bible of PCs says about BIOS but there is 0 info about BIOS or any of the configurations you can do within BIOS.

Instead, you can download separate file: "Software/BIOS Setup Guide", which covers all AsRock made AMD X670/B650/A620 MoBos.
PCI-E configuration starts from page 63.

This indicates that AsRock uses severe cost cutting methods, whereby there is one single BIOS for all AMD 600-series chipset MoBos they produce.
Looks like AsRock is moving more and more towards cheap end. 🤔