Supermicro 2021 BIOS bug?

I just found out that there is a bug in the BIOS of some Supermicro X9 (and earlier???) server boards with some processors (E3 XEON and maybe i3???). Just spent the last 25 minutes searching and didn’t come up with much info… Anyone khow better info than a single thread on Reddit and Serve The Home forums?

I know I have some affected servers, and they are running as domain controllers. Had in the budget to replace them last summer, then that got cut.

From the little bit of info I’ve found, these crash when you try to go into BIOS. The fix is to remove the battery and let the RTC reset or change the time to 2020 or earlier. It has been mentioned that Supermicro is looking into the issue, but not really concrete since I didn’t find anything on their website. Not sure if this is a BIOS UI only issue, or if IPMI is also going to cause a crash. Also concerned that a reboot may take the system down, and there is a big Microsoft Server patch coming this month which will require a reboot.

If you have more and better details, I’d very much like to read that info. Going to contact Supermicro now and see if they will at least put me on a mailing list for updates on this issue.

Reply I got from support:

We are aware of this issue for the X9SC_ series boards.

These boards had been end of life since 2015.

We are working on a fix right now and should have new BIOS posted in our website in a couple of weeks.

If you need to access BIOS setup then you can reset CMOS or change the system date in OS to a time before 1/2021, then access BIOS.

Here is a funny thing, even though I got a reply of January 7, the updated “fixed” BIOS is dated January 6.

It is up on the SuperMicro website now for each board, but does not show up on their NEWS page.

Reading the directions, you need a DOS boot device, RUFUS can create one on a USB. I have a little 2GB drive that I use for this sort of thing, but I know 8GB also works. Haven’t tried bigger drives.


  1. Save this file to your computer.

    1. extract the files to a DOS bootable device (such as a bootable USB stick, or CD).

    2. Boot to a DOS prompt and type AMI.BAT BIOSname.###.

    3. Do not interrupt the process until the flashing is complete.

    4. After you see the message of BIOS has completed the update, unplug the AC, clear the CMOS and plug in the AC and power on the system.

    5. Go to the BIOS setup screen and press F9 to load the default and press F10 to save and exit.