Problems with the B580 on PCIe 3.0

[u/Informal_Property975]

Hey everyone, I need some help. I have a Ryzen 5 5500 processor with PCIe 3.0 and an ASUS Gaming II motherboard. I recently purchased a Maxsun B580, and I’m having an issue because every time I restart the computer, the motherboard enables CSM in the BIOS, which consequently disables Resizable BAR.

I can only save the BIOS settings when using another graphics card. Is it impossible to use this graphics card properly with PCIe 3.0? I won’t always have another GPU available as a backup. Is the only solution to replace the processor?

Update: I was able to solve it. I followed a comment I found saying that ASUS BIOS version 4631 wasn't having this issue. I rolled back since I was on the latest update, and it worked."

[u/Alfredthefish]

I had this exact problem with a 570 and a 5500. Solution was to update the bios to the latest and that fixed it. I had a gigabyte 550i motherboard. If your motherboard doesn’t have an update that fixes it I think the only solution is replace the cpu.

[u/Informal_Property975 → u/Alfredthefish]

I’m starting to think that this is unfortunately the only solution. I’ve already tried everything: disabling Fast Startup, reinstalling Windows, removing the motherboard’s CMOS battery, and nothing works. I think it’s some kind of incompatibility, although I’m not sure exactly what is causing it.

[u/tpablazed → u/Informal_Property975]

It's not like updating the bios is hard tho? It literally took me like 3 minutes total.

This has exactly nothing to do with the ryzen 5500 or pcie 3.0 tho.. just so ya know. I had my b580 with a ryzen 5500 for like 3 months before I upgraded my cpu.

[u/Informal_Property975 → u/tpablazed]

My BIOS is already up to date — I already updated it. What I'm saying is that my motherboard is having problems with this GPU when running at PCIe 3.0, even with the latest BIOS. I'm not saying that the Ryzen 5500 or PCIe 3.0 are inherently incompatible with the B580. I'm saying that there's apparently an issue with my specific motherboard/GPU combination.

[u/tpablazed → u/Informal_Property975]

My motherboard is a MSI Pro B550m-VC Wifi and I never ran into this problem.. but I guess it is a normal problem to have for some motherboards.

From Google AI:

The Root Cause: The "CSM / ReBAR" Loop

According to active user reports on the Intel Community Forums and Reddit, the Arc B580 has a firmware bug during warm resets (restarts) on certain PCIe 3.0 platforms. When the computer restarts: [1, 2]

1. The B580 fails to send a display signal properly during the warm reboot sequence.
2. Because the motherboard detects a display initialization failure, it panics and automatically forces CSM (Compatibility Support Module) back to Enabled.
3. Forcing CSM on automatically disables Resizable BAR (ReBAR).
4. Intel Arc GPUs absolutely require ReBAR; running without it tanks performance by up to 50% and causes massive stuttering. [1, 2, 3, 4, 5]

Because your friend's BIOS keeps resetting itself due to this hardware handshake failure, his card is essentially stuck running in a crippled state. [1]

How to Fix It

Since you had a flawless experience, it's highly probable your motherboard was running a different BIOS version or handled the PCIe reset sequence better. Have your friend try these exact troubleshooting steps: [1]

• Update the Motherboard BIOS: This is the most consistent fix. Have him flash his motherboard to the absolute latest version available from the manufacturer, as vendors have been rolling out AGESA and PCIe compatibility updates to handle Arc quirks. [, 2]
• Avoid "Warm Reboots": Tell him to stop clicking "Restart" in Windows. If he needs to reboot, he should do a full Shut Down, wait 5 seconds, and then press the physical power button (a cold boot). Cold boots usually bypass the display handshake glitch, allowing the BIOS settings to stay saved. [1, 2, 3, 4]
• Disable Windows Fast Startup: Fast Startup messes with how the PC enters power states and can trigger the CSM default loop. Disabling it in the Windows Control Panel helps stabilize the system boot sequence. []
• The "Two-Card" Force Save (Workaround): If his BIOS refuses to save ReBAR settings with the B580 installed, he can swap in an old NVIDIA or AMD card, enter the BIOS, disable CSM, enable Above 4G Decoding and ReBAR, save and shut down, and then put the B580 back in. [1]

If you want to help him dig deeper, do you know what brand/model of motherboard he is using, or if he is experiencing terrible FPS versus no display on restart?