Hi all,
I’m experiencing a specific boot problem with my new AM5/RTX 5090 system running Fedora 42 and hoping for some insight.
The Problem:
When I power on the PC from cold with the monitor connected only to the ASUS TUF RTX 5090 (dGPU), I get no display output at all . This means no motherboard POST screen, and consequently, no GRUB bootloader menu. The screen remains blank.
However, the system is usable with the RTX 5090 under these specific conditions:
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Windows: Booting Windows directly with the monitor connected only to the RTX 5090 works perfectly from cold start, including POST display.
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Fedora - BIOS Workaround:
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Connect monitor to motherboard iGPU.
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Power on, enter BIOS/UEFI setup.
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Exit BIOS setup (saving or discarding doesn’t matter).
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Immediately switch the monitor cable to the RTX 5090 dGPU.
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The system then boots, displaying GRUB and loading Fedora correctly on the RTX 5090 .
- Fedora - OS Workaround:
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Connect monitor to motherboard iGPU.
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Power on and let Fedora boot fully to the login screen or desktop using the iGPU.
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After reaching the graphical login/desktop, switch the monitor cable to the RTX 5090 dGPU.
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The display successfully switches and works correctly on the RTX 5090 .
This pattern strongly indicates:
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The hardware is functional (proven by Windows and the workarounds).
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The installed NVIDIA driver within the booted OS works correctly and can initialize the card.
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The failure might during the initial firmware POST phase when the dGPU is the primary/sole display, specifically preventing the UEFI GOP (Graphics Output Protocol) used by GRUB/Linux pre-boot from initializing.
System Details:
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CPU: AMD Ryzen 9 9950X
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Motherboard: MSI MAG X670E TOMAHAWK WIFI
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BIOS: Version E7E12AMS.1H0 (Build Date 03/14/2025)
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GPU: ASUS TUF Gaming GeForce RTX 5090 OC Edition 32GB (TUF-RTX5090-O32G-GAMING)
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RAM: 64GB
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OS: Fedora Linux 42 (Workstation Edition) x86_64
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Kernel: 6.14.3-300.fc42.x86_64
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NVIDIA Driver: 570.144 from standard F42 rpmfusion-nonfree repo (akmod-nvidia proprietary module). (Note: Also tested 575 driver from Rawhide COPR with the same POST failure).
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(Context): CUDA tested working within booted OS.
Troubleshooting & Observations:
- BIOS/UEFI Settings:
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Initiate Graphic Adapter set to PEG.
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Resizable BAR, Above 4G Decoding: Enabled.
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CSM: Disabled.
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Secure Boot: Enabled(disable option tested and result in same failure).
- Linux Config (Likely irrelevant for POST failure): Nouveau blacklisted, nvidia-drm.modeset=1 set, driver module confirmed building.
Request:
The core issue appears to be the motherboard firmware (BIOS/AGESA) failing to initialize video output via GOP on the dGPU during POST when it’s the primary cold boot device for the Linux path. Windows handles this differently, and the Linux OS driver can recover after boot.
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Is this “no POST screen unless BIOS entered or OS booted via iGPU first” behavior a known issue with AM5/X670E/Ryzen 9000 and high-end NVIDIA cards (RTX 40/50 series), potentially specific to certain BIOS/VBIOS combinations?
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Could the MSI BIOS E7E12AMS.1H0 have bugs related to GOP initialization for this GPU?
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Why might entering/exiting BIOS setup allow GOP to work subsequently? Does it perform a more thorough/different GPU init?
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Is a VBIOS update for the GPU the most likely fix for such a POST-level initialization failure?
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Are there any obscure BIOS settings (PCIe training, power states, GOP handling) that might influence this specific early initialization failure?
Any insights into resolving this firmware-level POST/GOP initialization problem for the Linux boot path would be greatly appreciated.
Thanks!