Hi all,

Yes, it's ANOTHER USB issue, but promise of been reading and searching all over the place before posting...

 

I've been doing a bunch of disk changes lately, so I'm currently in a state of not having a valid parity disk.

Having said that, everything has been running fine, and I was just about to put in the last disk and close it all up when I [stupidly, I know...] decided to update the BIOS while I had the machine out on the bench.

MB is Aorus B450. Bios went from v50 to v64.

 

After updating that, the machine won't boot the unraid USB.

It seems to freeze up and sits on the MB splash screen, but doesn't progress from there.

 

I've checked all the usual suspects...
Fastboot is off.
Drive is visible from BIOS and is set to boot from there.
UEFI is set on BIOS and checked the usb folders to make sure EFI didn't have a hyphen after it.

 

I've tried:

Booting another OS from USB - that works fine, and all disks are visible.

Reinstall unraid to the original USB using a backup zip from connect - still freezes.
Install fresh unraid to new USB stick - still freezes.

 

I gather there has to be SOMETHING in the BIOS that's stopping unraid running, but can't see what it might be for the life of me.

Any thoughts would be more than welcome!

Cheers!

Have you done memtest?

No, I hadn't.

Just running it now shows thousands of errors.

All of that was working before, though...

 

Any ideas what might have caused this in updating the BIOS?

 

Edit:
Sorry... for info, I ran the memtest86 scan, as I can't get to the unraid boot screen.

It's showing the 4 x 16gb sticks correctly, but the initial test was all errors.
I've turned on the XMP Profile 1 settings in the BIOS and re-run memtest again. No errors so far...

Someone on Reddit pointed out this conversation.
From memory, the "Storage Boot Option Control" is set to UEFI, and the "Other PCI Device ROM Priority" is Legacy already.

Will check that and the CSM Support once the memtest is done.

Similarly to that reddit post, I also have an SAS card in, so will remove that at some point in the proceedings, too.

Edited January 27, 20242 yr by newillusions
initial freakout :)

Ok, so memtest has run all 4 passes and no issues there.

SAS card disconnected.

Confirmed that "Storage Boot Option Control" is set to UEFI, and the "Other PCI Device ROM Priority" is Legacy.

 

Still seeing exactly the same issue, though. It's getting to the splash screen and freezes.

 

Any other areas I should be looking at?

Can you boot another computer from that flash drive?

Only have my laptop to test with, and that didn't boot from the USB, however I wound up in a bitlocker key screen [it's normally running windows, and had to turn off encryption to test the USB] so not convinced that counts as an actual fail...

 

I did try to boot the unraid machine from a fresh install on a new key before, which failed in the same way.

Will try that again now that the XMP profile is active.

 

Also, confirmed that USB is active in POST based on BIOS settings.

1 minute ago, newillusions said:

Will try that again now that the XMP profile is active.

You normally want XMP,profile turned OFF for maximum stability as turning it on is by definition overclocking.

Yeah, it was off previously, but that caused all the errors during the memtest.

 

Edit:
I don't remember it being turned on previously, but it has been several years since I set the machine up, so may have just forgotten.

Edited January 28, 20242 yr by newillusions
Added info

Ok, so nothing seems to be working at this point, so I've rolled back to BIOS v40 v50 and it all boots up straight away...

 

Edit:
Ended up on v62 and it all boots up nicely. there's something [not clearly described] about v64h having some UEFI changes, so guessing that's the culprit, without having access to any more info.

 

Thanks all for your suggestions.

Edited January 28, 20242 yr by newillusions
Added Info

Sorry to resurrect an old thread, but your suggestion to change bios helped me as well. I have a x870e MSI tomohawk motherboard. And after updating my bios unraid would refuse to start. Didn't matter what USB drive I tried, what port I used (3.0 or 2.0) it just refused to start. It wasn't until I read this post that I started downloading all the bios'ies i could find on my motherboards official site, to find one that worked.

And I found one eventually, it even fixed my issue that I was having that my server would not boot unless I moved my USB to a different port. If I didn't do that my server would just boot again, to a solid black screen.

On 2/2/2026 at 4:49 PM, Mrtj18 said:

Sorry to resurrect an old thread

I actually think this needs to be bumped all the way to the top, because there are going to be support tickets coming left and right!

I can confirm this issue also affects the Gigabyte X670E AORUS Master, and the failure goes beyond just blocking USB boot.

After updating to F42a, Unraid would no longer boot from USB. Rolling back to F41 did not fix it. Only after downgrading to F39 was I able to boot Unraid again.

Here’s the BIOS progression:

• F42a (Mar 2026)

  • AGESA 1.3.0.0a

  • DDR5 vulnerability fix (CVE‑2025‑6202)

  • Result: Unraid USB will not boot.

  • Additional issue: All front‑panel USB ports became unstable. I could not reliably format, flash, or write to any USB drive connected to the case ports. Attempts to repair the Unraid boot device on those ports failed completely and even caused corruption.

  • Only the rear motherboard USB ports were stable enough to restore the boot device.

• F41 (Feb 2026)

  • AGESA 1.2.8.0

  • Result: Unraid USB still will not boot.

• F39 (Dec 2025)

  • Pre‑2026 AGESA

  • Result: Unraid boots normally again. USB ports behave normally.

Based on this, it appears that all 2026 BIOS releases for this board break UnRaid USB booting and likely also other AMD AM5 boards, likely due to AGESA changes and new security hardening. The USB instability in F42a suggests deeper changes to the USB initialization stack, not just the bootloader path.

For anyone troubleshooting similar symptoms: F39 is currently the last known‑good BIOS for Unraid on the X670E AORUS Master.

I've sent out a message to LimeTech and will also send out a message to gigabyte regarding this problem.

Edited April 4Apr 4 by un1ty

Use the Limine bootloader instead: https://forums.unraid.net/topic/196349-black-screen-after-usb-boot-msi-x870e-carbon-ryzen-9950x-rtx-4070-ti-super/?do=findComment&comment=1607672

On 4/5/2026 at 9:48 AM, JorgeB said:

Use the Limine bootloader instead: https://forums.unraid.net/topic/196349-black-screen-after-usb-boot-msi-x870e-carbon-ryzen-9950x-rtx-4070-ti-super/?do=findComment&comment=1607672

Yep, this was also the feedback I got from unraid.
But just to add to the topic, I did receive a custom bios from gigabyte based of F42a, which allowed me to boot with the existing bootloader.

Here is the message I received after confirming that this modified bios worked;