Intel B50 UEFI boot issue on X470 system

[hege]

Hi,

I have an issue with a B50 card that works on an X570 desktop motherboard (Asus Crosshair VIII Dark Hero), but refuses to boot on an X470 server board I want to run this GPU in (ASRockRack X470D4U with a Ryzen Pro 5750G CPU, BIOS version L4.20 and beta BIOS L4.29A). I have followed the quick setup guide and set the motherboard to UEFI mode (CSM disabled) with ReBAR and SR-IOV enabled. After powerup, the B50 is recognized and saved in the System Inventory of the BMC chip, but right before the OS is loaded, the board KVM shows NO SIGNAL and resets the board. After the reset, the card is no longer recognized, so when the OS finally boots, the card is no longer shown in the PCIe hierarchy. The card also gets quite warm, much warmer than at idle in Windows.

Since I can boot on my other system, I have installed the Intel Arc Pro 2025Q3 drivers in windows which did a firmware upgrade, but the card still doesn't boot on the X470D4U board. Then I let the intel updater do another round of update (2025Q4 Arc non-pro drivers?) with another firmware update, and it still shows the same non-booting behavior.

I'm a bit lost as to why this particular combination isn't booting. I have tried all possible combinations in the BIOS (ReBAR, IOMMU, PCIe bifurcation), but it all leads to the board resetting right before the UEFI loads the OS. 

Is there any known issue with the B50 not booting on certain Ryzen based systems?

thanks!

 hege

[hege]

Updated the B50 with 32.0.101.8306 driver in windows, which updated the card firmware. Unfortunately the booting issue is still there in the X470D4U system.

[Mike_Intel]

Hello hege,

Thank you for posting in Intel community Forum.

For me to better understand and diagnose the issue further, let me ask you to provide detailed responses to the following questions. This information will help me isolate the problem and determine the most appropriate course of action moving forward.

1. Just to check, you can still see the splash logo and you can enter the BIOS, the issue is when the system starts to boot into the OS?
2. What is the OS of the system?
3. Did you also check the compatibility of this card to the boards that you tried to use?

If you have questions, please let us know. Thank you.

Best regards,

Michael L.

Intel Customer Support Technician

[hege]

Hi Michael, thanks for the reply. Here is some additional info.

I am using the AST2500 BMC IPMI's KVM to access the system, there is no monitor connected. After the first power up of the motherboard with the B50 connected, the boot progresses to the splash screen, and the IPMI is updated with the B50 PCIe information (system inventory). However, I can not enter the BIOS, and the OS doesn't boot. Instead, the motherboard resets and the boot process restarts. After the reboot, I can enter the BIOS and the OS (Debian testing with Linux Kernel 6.17) also boots. However, lspci does not show the B50 card at all and no log message from any intel related components (xe driver). The IPMI system inventory after the second boot is also updated and it no longer shows the B50 as a PCIe device.

I have tried to toggle every single option in the BIOS that could be related, but in every case the same thing happens. Except when I set the BIOS to boot with CSM mode, it boots the first attempt but the card is also missing in the OS (this would be expected since the B50 requires UEFI boot mode and won't be recognized in CSM legacy mode).

Regarding compatibility, the X470D4U has PCIe 3.0 and Resizable BAR support. I believe that should be compatible with the B50, unless there are additional compatibility issues with older Ryzen systems.

I have reached out to the motherboard vendor as well (ASRockRack) to see if they can assist with debugging, but it's not clear to me where the compatibility issue comes up exactly.

regards,
hege

[Mike_Intel]

Hello hege,

Thank you for the qucik response.

Let me clarify some information about your set up. Please help provide the following details:

1. Can you send some photos of the set up?
2. If you are not using a KVM or if you have a normal set up with a monitor. Is it working fine?
3. For me to check the hardware and the installed drivers, kindly generate the SSU logs of your system. Please refer to the link below for the steps:

How to get the Intel® System Support Utility Logs on Windows*

If you have questions, please let us know. Thank you.

Best regards,

Michael L.

Intel Customer Support Technician

[hege]

Hi Michael,

I don't have a good photo of the system, only a very dark video that captures the IP KVM (via AST2500 BMC's web interface) and the post codes on the motherboard: https://youtu.be/XCRzOBptW6Y?si=NyiO0JjqzCfgLxw4.

Normally at the end of the boot cycle I get code 99 on the splash screen, then code 92 and the UEFI bootloader (GRUB) loads. With the B50 I get code 99 and then an immediate reset of the motherboard with the boot process restarting. Which repeats one more time and then the OS boots, but the B50 is no longer recognized on the PCI-e bus (it's missing from the BMC's inventory and lspci doesn't list it either).

I currently don't have any DP output connected to the card. I can try getting a miniDP adapter, but in my setup I would like this card to work completely headless, so I can't leave a monitor connected just to make the card boot (and besides, the card boots 100% reliably on another similar motherboard).

So far I have tried the following:

1. Disconnected all other PCIe, USB and SATA devices, and left only the B50 connected to either of the x16 slots. No difference.

2. Enabled / Disabled ReBAR, CPU virtualization, SR-IOV. No difference.

3. Enabled / Disabled various  toggles in CBS > NBIO Common options (DMAr, ARI). No difference.

The only way I can boot the X470D4U system is if to fully power down the power supply, and power up. The first cold boot will about 50% of time detect the B50 and boot into Linux, with the B50 visible in lspci and the xe driver loaded as it should. However, any time after that with a warm reboot, the card disappears and will no longer be present in lspci output.

On my other AMD AM4 system (ASUS X570 motherboard), the card boots perfectly with no problems - so it's not a faulty B50 card.

All evidence points at some compatibility issue with either AMD's AGESA version (1.2.0.Cc on ASRockRack and 1.2.0.F on ASUS) or the specific implementation of the UEFI from ASRockRack.

So far the motherboard support just replied that AMD CPUs sometimes don't work with Intel GPUs, which I find extremely disappointing, and I refuse to believe, since the B50 card's documentation doesn't advertise that it won't work with older AM4 motherboards; so I would like some debugging help.

I'm hoping maybe there is a way to get a fix deployed either via a B50 card UEFI firmware update, or a Motherboard UEFI firmware update. I expect Intel and AMD and motherboard vendors to be in contact about required BIOS updates for compatibility issues like this, and an update to be provided by either party.

thanks,

 Hege

[Mike_Intel]

Hello hege,

Thank you for the quick response.

Based on the initial information that you provided, it seems that this is a combability issue.

However, I want to further investigate this that is why I requested for SSU. I will also have this checked by our Engineers that is why I am asking more details. Let me request for the SSU again for me to have this investigated:

How to get the Intel® System Support Utility Logs on Windows*

If you have questions, please let us know. Thank you.

Best regards,

Michael L.

Intel Customer Support Technician

[hege]

Hi Michael,

I have installed windows 11 and installed the B50 drivers and collected the SSU logs as requested on the affected X470D4U motherboard. On the first cold boot, the card is recognized and I'm able to use it. After rebooting the machine, the card is no longer recognized.

After this, no matter how many times I reboot, the card is never recognized again and I have to power off the computer completely. Sometimes I also have to load BIOS defaults (and set the required settings back: CSM:disabled, ReBar:enabled, etc.). After that, the card boots once, and works until I reboot.

Any help appreciated!

thanks,

 Hege

[Mike_Intel]

Hello hege,

Thank you for the information provided.  

I will do further research on this matter and post the response on this thread once it is available.

If you have questions, please let us know. Thank you.

Best regards,

Michael L.

Intel Customer Support Technician

[hege]

Thank you Michael! Further note: I purchased another B50 for testing, and that card is behaving exactly the same way, so it's not a hardware problem on the Arc side, and I doubt it's a hardware issue on the motherboard side either since a similar spec GPU from another brand works perfectly.

So far ASRockRack didn't reply with any concrete suggestions, I'm waiting to hear if they have updated BIOS available for testing.

[Mike_Intel]

Hello hege,

Thank you for patiently waiting for our update.

Upon further checking the configuration and set up and based the article Intel® Arc™ Pro Graphics – Desktop Quick Start Guide, only AMD 500 Series motherboard with Smart Access Memory enabled and newer series motherboards are compatible with the Intel Arc Pro B50.

This means that the cause of the issue is a compatibility issue between the X470D4U and the Arc B50 GPU.

Thank you for understanding and have a great day. 

Best regards,

Michael L.

Intel Customer Support Technician

[hege]

Hi Michael,

I understand that the B50 requires Resizable BAR (AMD Smart Access Memory). My Motherboard vendor has BIOS available that enables that feature. I am also able to sometimes boot the B50; see the SSU log attached above when the B50 was recognized and loaded, and I was seeing Resizable Bar: enabled in green in the Arc driver. I'm also getting the same issue regardless of whether this setting is enabled or not.

Thanks for calling out that B450/X470 is not on the officially supported list, so it's very unlikely I would get help either from Intel or ASRockRack on this, I'm going to have to return the B50.

thanks,

 Hege

[hege]

Hi, 

sorry to add a reply here, but after further reading, I found *multiple* posts here about Battlemage series Arc cards disappearing after warm reboots on AMD AM4 platform, e.g. https://community.intel.com/t5/Intel-Arc-Discrete-Graphics/Warmboot-on-Intel-arc-b570-and-B450-endless-blackscreen-and/m-p/1732342 and https://community.intel.com/t5/Intel-Arc-Discrete-Graphics/Warm-Reboot-Hanging-Restart-problem-with-Intel-Arc-Pro-B50-and/m-p/1733211#M32425

I'm confident that these all have the same root cause. Can we reopen the investigation of B50 card warm reboot issues on older AM4 platforms?

I'm able to boot the card once after a cold start, but any reboots after that will make the card disappear, same as the other reports.

[telsauers]

I second this! Please have your engineers investigate!!

[hege · Accepted solution]

Further update: a 5900X in the same Motherboard works perfectly, it's the 5750G that's causing this behavior.

Intel Engineering has been able to reproduce this problem between AMD Cezanne APUs (5500, 5600G, 5650G, 5700, 5700G, 5750G) and B580. Mid November 2025.

The issue seems to be caused by the specific PCIe reset sequence that these AMD CPUs have implemented.

Let's hope a VBIOS fix is in the works!

https://github.com/IGCIT/Intel-GPU-Community-Issue-Tracker-IGCIT/issues/1262