CSM Forced Enablement Phenomenon

[tougen]

Please note that this text has been translated using a translation tool, so there may be some unusual expressions. Thank you for your understanding.
After using a Windows 11 PC with an RTX 3050 for about two years without any issues, I replaced it with a B580. This led to a phenomenon where, upon restarting Windows 11 or similar actions, the monitor's input signal was not detected, the screen remained dark, and the PC repeatedly restarted multiple times. Even after the restart cycle ended, the screen stayed dark. I had to force shut down and turn the power back on, which resulted in CSM being forcibly enabled. I noticed this issue when I saw that re-bar was disabled in Intel Graphics Software and later confirmed that CSM was enabled in UEFI.
Hereafter, I will refer to this as the "CSM Forced Enablement Phenomenon." Although I managed to reach a state where it seems no problems occur, it feels quite unstable, so I have currently reverted to the RTX 3050. It appears that the problem does not occur if specific USB devices are not connected, but during clean installations, the problem arises under any conditions. I am concerned that a future Windows 11 update may cause the problem to resurface. Therefore, with the hope of future improvements, I would like to report this issue. The devices used are as follows:

Windows 11 Home (initially: 24H2 / during clean install and subsequent troubleshooting: unknown)
Motherboard: gigabyte b550m ds3h Rev1.4 (bios: FDc Sep,2023 / FFc Sep 02, 2024) *FDc is currently not available
CPU: ryzen5 5500

RAM: 8GB x4 DDR4 2666MHz

SSD: ADATA LEGEND 800 1TB, ADATA SX6000PNP 512GB
GPU: asrock b580 challenger (driver: possibly 32.0.101.6559, installed after Feb 23, 2025)
PSU: enermax marble bron 550W
Monitors: MSI PRO MP2412 (FHD, 100Hz, DP) / LG 23MP65 (FHD, 60Hz, HDMI, connected and tested only during screen blackout)
Keyboard: Sanwa Supply SKB-SL32BK / Mouse: Elecom M-SH30DBSK, Corsair Gaming Harpoon RGB Mouse

Additionally, I have tried using DDU, clearing CMOS, checking UEFI settings (disabling fast boot and secure boot, confirming UEFI mode only, 4G decoding, PCIe primary output, and Resizable BAR), updating the BIOS, and replacing the monitor, but none of these were effective.

(1)On the first day after replacing the GPU, it operated without issues, even under high loads such as gaming and using ComfyUI. Restarting after installing the graphics driver and related software did not seem to cause any problems.
(2)On the day after replacing the GPU, I noticed that Intel Graphics Software could not be launched. To reinstall, I uninstalled the graphics driver and related software, and during the required restart, I encountered the "CSM Forced Enablement Phenomenon."
(3)Furthermore, when attempting to disable CSM while it is enabled and the B580 is attached, the "CSM Forced Enablement Phenomenon" reoccurs when saving the settings and exiting UEFI, making it impossible to disable CSM. Note that Windows 11 is installed in GPT, and it can still boot with the B580 as long as CSM is enabled.
(4-1)Even when attempting to clean install Windows 11 with the B580 attached and CSM enabled, the system repeatedly restarts and encounters a phenomenon where the screen remains dark. The same happens with the Linux Ubuntu 24.4 live USB.
(4-2)It was later found that when trying to install Windows 11 with the B580 attached and CSM disabled, the installation proceeds smoothly until the restart during the installation process, at which point the "CSM Forced Enablement Phenomenon" is encountered.
(4-3)Therefore, all the multiple clean installations were carried out with the RTX 3050 attached and CSM disabled.
(5-1)When encountering the "CSM Forced Enablement Phenomenon," I replaced the GPU with the RTX 3050 and disabled CSM in UEFI, allowing Windows 11 to boot. After using DDU in Safe Mode and shutting down, I reattached the B580, and Windows 11 booted with CSM disabled.
(5-2)There were no issues during the necessary restart after installing the graphics driver and related software.
(5-3)However, when disabling CSM with the RTX 3050 attached, clearing CMOS, and then attaching the B580, UEFI could not start and kept restarting. After force shutting down and starting UEFI again, CSM was enabled.
(6-1)When restarting Windows 11 with the B580 and CSM disabled, the "CSM Forced Enablement Phenomenon" occurs. However, I noticed that turning off the power of the wireless mouse immediately after the restart prevents the phenomenon. When I restarted under the same conditions using a wired mouse, the phenomenon did not occur.
(6-2)However, if I try to disable CSM using a wired mouse while encountering the "CSM Forced Enablement Phenomenon," it still occurs as long as I am using the B580.
(7)I apologize, but I am unable to provide a bug report(SSU) as I am currently using the RTX 3050. Since I have spent considerable time on the verification work, I would like to maintain a stable environment for a while.
(Note) My memory is vague, but according to my notes, when starting Windows with CSM enabled and trying to enter Safe Mode by holding down the shift key and pressing restart, I encountered the repeated restart phenomenon and could not enter Safe Mode.

[Kahama]

It sounds like you’ve done an impressive amount of troubleshooting already, from swapping GPUs (RTX 3050 to B580), testing BIOS settings (CSM, Resizable BAR, etc.), performing clean installs, and even experimenting with USB peripherals. The "CSM Forced Enablement Phenomenon" you’ve described seems particularly tricky, especially with its ties to restarts, monitor signal loss, and UEFI behavior.

Since you’re reporting this with the hope of future improvements, I’d like to highlight a few points that might help others in the community or Intel support team provide insights:

1. CSM and GPU Compatibility: Your observation that the B580 forces CSM to enable—and that disabling it leads to the phenomenon—suggests a potential compatibility issue between the ASRock B580 Challenger GPU and your Gigabyte B550M DS3H motherboard, especially with UEFI mode and Windows 11’s GPT requirements. This could be related to how the GPU initializes in UEFI-only mode.

1. USB Device Impact: It’s interesting that specific USB devices (like the wireless mouse) seem to influence whether the phenomenon occurs. This might point to a power delivery issue, an interrupt conflict, or something specific to the B580’s driver interaction with USB controllers during boot.

1. Driver and BIOS Versions: You mentioned the GPU driver might be version 32.0.101.6559 (post-Feb 23, 2025) and tested BIOS versions FDc and FFc. It could be worth confirming the exact driver version when you reinstall the B580, as well as checking if newer BIOS updates address UEFI/GPU stability.

[tougen]

I forgot to mention that the memory is a mixed configuration of ADATA D4D3200-8G2A2 3200MHz 8GB x2 (PC4-25600) and G.SKILL F4-2666C19D-16GNT 2666MHz 8GB x2 (PC4-21300), and the previously mentioned values are the actual operating frequencies.

[tougen]

Thank you for your response.

To get straight to the point, it seems that the RAM configuration is not the issue.
While explaining the verification methods in detail would be lengthy, I will summarize the findings as follows:

(1)RAM: I tried various configurations to avoid mixed setups, such as using 2 sticks, 1 stick, and swapping out RAM. I also changed various conditions (monitor, USB ports, hardware configuration including the second M.2 socket, and CMOS clear). However, I could not recover from the state where CSM is forcibly enabled.

(2)Event Viewer: The Event Viewer appears normal, but during most of the verification work, despite repeatedly force shutting down (holding down the power button), the logs for those periods do not seem to be saved. Therefore, it appears that Windows is not booting at all.

(3)USB 3.0 Front Panel: When attaching a device to the front panel with B580 installed, CSM is forcibly enabled during reboot. However, attaching the device to the back panel does not necessarily prevent this issue.
Ideally, I wanted to test by disconnecting the front connector for USB 3.0 from the motherboard, but it was difficult to remove due to strong attachment. As an alternative, I disabled USB Legacy Support and tested, but there was no change.

(4)Safe Mode Issue: While rebooting and shutting down works without problems under appropriate configurations, attempting to boot into Safe Mode forcibly enables CSM.

Additional Note: In addition, I found several similar reports on Reddit, and two of them were using Ryzen 5 5500. A common point in all reports seems to be that the CPU only supports PCIe 3.0.

[jbruceyu]

Ensure your BIOS is up to date, as updates can sometimes resolve compatibility issues. Check Boot Settings boot type is set to UEFI only, not the Legacy and UEFI. Update to the latest graphics driver version 32.0.101.6632 using Display Driver Uninstaller (DDU) for a clean installation

-bruce

[TheExpertGuy]

BIOS/UEFI Settings & Firmware Version. It may be worth checking if there's an updated version of the BIOS/UEFI firmware available for your motherboard, particularly one that could address compatibility issues related to CSM or your specific CPU model (Ryzen 5 5500). In other way, motherboard manufacturers release updates to address issues like this, especially related to CPU compatibility or PCIe configurations.

CSM and UEFI Boot Mode. Disabling CSM: Given that CSM is being forcibly enabled, you should ensure that your system is set to boot exclusively in UEFI mode rather than legacy BIOS mode. The presence of certain devices (like USB peripherals) or configurations can trigger CSM to be enabled automatically. Try these steps:

• Enter BIOS and ensure that Secure Boot is enabled (if not already).
• Check the Boot Mode setting and make sure it's set to UEFI only.
• Disable CSM explicitly if there is an option to do so.

• Ensure that your boot drive is formatted with GPT (GUID Partition Table), which is required for UEFI mode. If the drive is using MBR (Master Boot Record), the system may revert to legacy BIOS mode, triggering CSM.

CPU and PCIe Configuration. You said that several reports involved users with Ryzen 5 5500 CPUs, which only support PCIe 3.0. It could be a good idea to check how your system is handling PCIe lanes and whether any devices are causing the system to fall back to PCIe 2.0 or Legacy mode. If there is a discrete GPU installed, verify whether it's seated properly and if it's introducing any issues during boot (particularly related to PCIe slots or configurations). Try booting without a dedicated GPU and using integrated graphics (if available) to check if the issue persists. External Devices and USB Ports. The issue you noted with the USB 3.0 Front Panel could be related to a specific USB controller or driver issue that forces the system to fall back to CSM. Even though you've tried disabling USB Legacy Support in BIOS, I recommend testing again with all USB devices disconnected entirely and observing whether CSM is still being enabled. If possible, disconnect the USB 3.0 front panel connection temporarily, even if it's difficult to remove. You might also try disabling XHCI hand-off (which handles USB 3.0/USB 3.1 devices) in the BIOS, as this can sometimes impact boot behavior. Safe Mode & Windows Boot Issues. You said that Safe Mode forcibly enables CSM. This could be related to how Windows is trying to boot into Safe Mode and might be causing the system to revert to CSM mode due to drivers or hardware configurations that aren't fully compatible with UEFI. Try booting from a Windows installation USB (or recovery drive) and running Startup Repair to see if it can resolve any boot issues related to UEFI or legacy boot modes. Additional Diagnostics. If you've already done a clean installation of Windows, consider running a chkdsk (Check Disk) or sfc /scannow command from the Windows recovery environment to ensure there are no underlying file system or boot configuration issues. You could also try testing with a different OS (e.g., a live Linux distribution) to check if the issue is related to Windows-specific booting or a broader hardware compatibility issue.

If you still experience issues after all of this, it could be a more niche compatibility issue between the motherboard and the Ryzen 5 5500 CPU, potentially requiring an update to the BIOS/UEFI to resolve.

[tougen]

To kahama, jbruceyu, and TheExpertGuy, thank you for summarizing the key points so clearly and for the various pieces of advice. Based on your advice, I have attempted to resolve the issues and the situation is improved somewhat. At the very least, the system seems to be functioning at a usable level for the time being. Thank you very much.

For some reason, the comments that were previously displayed have disappeared, and kahama's comment has appeared instead, making my previous comment somewhat irrelevant.

For the benefit of those who have recently encountered similar issues, I have summarized my experience below. However, even with the same USB port configuration, different results may be obtained, so please note that the following outcomes are not guaranteed.

(1)When CSM is not forcibly enabled:

Shutdown, sleep, UEFI settings, and normal startup should be possible.
Restarting is inconsistent, even with the exact same configuration. Sometimes it works and sometimes it doesn't. The cause remains unknown. Additionally, the issue has never occurred during the initial driver update and subsequent restart.

Safe mode startup is likely impossible. I vaguely remember that sometimes the screen would go black before reaching the blue screen for Startup Settings, and sometimes it would reach the blue screen.

Performing a clean install should proceed smoothly until a certain point, but the CSM Forced Enablement will likely occur during the necessary restart process.

(2)When CSM is forcibly enabled (Secure Boot disabled):

Shutdown, sleep, UEFI settings (except for the operation to disable CSM), normal startup, and restart seem to be all possible.

Safe mode startup seems to be impossible. However, there was one instance where I was able to execute startup repair, although the repair was unsuccessful.

In this state, it is impossible to boot from Windows installation media, Linux Live USB, or the boot sector of storage devices with CSM disabled.

When faced with this situation, the solution appears to be either preparing another GPU to reconfigure CSM settings or using the method below suggested by TheExpertGuy.

(3)Regarding Secure Boot:

Among the changes I have made so far, enabling Secure Boot had a noticeable impact.

If Secure Boot is enabled in advance, it seems to prevent CSM Forced Enablement even if the issue begins to occur. While this does not prevent the issue from starting, unlike the usual CSM Forced Enablement Phenomenon, the system endlessly restarts. After a forced shutdown and subsequent startup, CSM remains disabled, although it is unclear if this is the appropriate solution.

While CSM Forced Enablement occurs and you set CSM to disabled and Secure Boot to enabled, the system will endlessly restart, but after a forced shutdown and subsequent startup, CSM remains disabled.

However, in the UEFI of my motherboard, the Secure Boot setting does not appear unless CSM is disabled first, so these behaviors may vary depending on the motherboard.

At this stage, it still seems almost impossible to perform tasks that involve restarting. It will be necessary to observe how the system behaves during software installations and Windows updates that require restarts. However, it seems unrealistic to perform major updates with this configuration. Perhaps there are compatibility issues during initialization sequence.

[Grishak]

Just purchased an ARC B580, I also use the Ryzen 5500 and have the exact same issues described above. This I believe is because the processor itself operates on PCIe3 in a PCIe4 motherboard. I believe the Ryzen 5 5500 is the CSM problem for being paired poorly, with that being said I have a 5700 on the way that supports PCIe4 and I will post on Friday if that resolved the issue.

[micky4000]

Hi,

I recently bought an ARC B580 (Asrock B580 Challenger), too. Installed it in my Gigabyte GA-A320M-S2H V2 (bios: F57g) with Ryzen 5 5500, 16GB RAM and get the same problem with the forced CSM activation.

• Cold-Boot works everytime flawlessly for me - I can go into BIOS/UEFI-settings or boot Windows 10
• Changing settings to CSM disabled, ReBar, Above 4G to enabled - save settings, one reboot - ok. Win 10 starts with enabled ReBar
• Next warm-boot (Win 10 loaded before or strg-alt-del directly after saving UEFI settings) leads to error-beep from the mainboad - Win 10 boots without signal at the monitor!
• Forcing cold-boot and reenter BIOS/UEFI it shows now CSM was reactivated

I installed the latest drivers for the B580 with the integrated firmware updates, but no improvement.

It seems that the B580 does not initialize properly after the second warm boot until the next cold boot.(?)

[tougen]

Thank you for sharing your experience, micky4000. Although this is just my personal assumption, it might indeed be the case.

By the way, I wanted to report that I have successfully completed multiple scheduled Windows 11 updates since then. Even when selecting the "Shut down after update" option—where the update process includes a restart—I have not encountered any issues with these specific restarts.

However, as I mentioned before, I did experience problems when restarting as part of a clean installation of Windows 11. Therefore, I plan to swap out my GPU before proceeding with the 25H2 update.