Z790 Hero BIOS downgrade

[Tron64]

I've upgraded my Z790 Hero from BIOS version 0703 to 0813.

Before the update, my RAM runs stable at 4000 MHz. With 0813, it looks like I have to reduce the speed to 3400 MHz (memtest is still running).

Tried to downgrade to 0703. It says the BIOS file is invalid.

Is it possible to downgrade BIOS from 0813 to 0703?

[JohnAb]

Actually I don't know as I have another board/BIOS, but I have seen some comments that suggest it is not possible. However, I haven't seen this expressed clearly.

Does anybody know for sure? - can 0813 be rolled back to a previous BIOS?

[iBruceypoo]

JohnAb wrote:
Actually I don't know as I have another board/BIOS, but I have seen some comments that suggest it is not possible. However, I haven't seen this expressed clearly.

Does anybody know for sure? - can 0813 be rolled back to a previous BIOS?

I've rolled back many many bioses with the EZ Flash 3 Utility, I had issues with 0078 and 0088 Apex experimental bioses causing instability - then rolled-back to 0809 for awhile.

Currently using Apex 0812, it's perfectly fine so far.

------

I've heard bios flashback at the rear I/O USB port and button is the BEST way to flash, but I never use it.

[Luis00014]

Asus has really messed us up. They have known about these issues since 2022 and still they continue to sell these mobos with an unstable bios version that doesn't allow us to roll back to a stable bios version.

I was only able to roll back to version 0810, but that bios version also is not stable. I tried rolling back to 0809 and 0801 from both 0813 and 0810, and when manually flashing the bios it gets stuck in a permanent/steady blue light instead of blinking. Using the ez flashback tool in bios tells me these are not proper bios versions, 0801 or 0809, so we are stuck with bios versions that are not stable at all and cause BSODs.

Asus, please fix this problem you caused asap.

[Saltgrass]

I have been having the same situation with my system. It ran fine for several weeks with 4 sticks of G.Skill 6400 DDR 5 memory @6400 speed. Then it first showed a 54 on the LED regarding memory then after some changes it went to 55, which is still related to memory.

I am currently testing with only 2 sticks at a time but will try again to get all four to work and if not, I might roll mine back. The flash drive that comes with the system does not have the 703 Bios but a usable drive needs to be fat32 and single partition. Since the included drive starts an image of some type, it may be restricted for this purpose.

[iBruceypoo]

Saltgrass wrote:
I have been having the same situation with my system. It ran fine for several weeks with 4 sticks of G.Skill 6400 DDR 5 memory @6400 speed. Then it first showed a 54 on the LED regarding memory then after some changes it went to 55, which is still related to memory.

I am currently testing with only 2 sticks at a time but will try again to get all four to work and if not, I might roll mine back. The flash drive that comes with the system does not have the 703 Bios but a usable drive needs to be fat32 and single partition. Since the included drive starts an image of some type, it may be restricted for this purpose.

I wouldn't use that flash drive that arrives with the motherboard.

Grab an inexpensive USB drive and use it for all your bios updates and rollbacks and utility files. Place each bios in a separate folder and "label the folders" with their respective bios numbers for future reference.

And so you don't CONFUSE the bioses, since once renamed as .CAP files they all will read the same - MZ790H or MZ790A etc. 🙂

[Tron64]

Saltgrass wrote:
I have been having the same situation with my system. It ran fine for several weeks with 4 sticks of G.Skill 6400 DDR 5 memory @6400 speed. Then it first showed a 54 on the LED regarding memory then after some changes it went to 55, which is still related to memory.

I am currently testing with only 2 sticks at a time but will try again to get all four to work and if not, I might roll mine back. The flash drive that comes with the system does not have the 703 Bios but a usable drive needs to be fat32 and single partition. Since the included drive starts an image of some type, it may be restricted for this purpose.

I also use 4 ram sticks (which is a pain). Each BIOS version requires different manually adjusted speeds.

Anyway. Tried 3 different USB sticks (with repartitioning, reformatting & redownloading) in BIOS and using the BIOS USB back port. No luck.

[JohnAb]

Tron64 wrote:
I also use 4 ram sticks (which is a pain). Each BIOS version requires different manually adjusted speeds.

Anyway. Tried 3 different USB sticks (with repartitioning, reformatting & redownloading) in BIOS and using the BIOS USB back port. No luck.

Very odd. I did look at the 0813 BIOS release notes and they didn't say anything about rolling back (or not). Have you tried using EZ Flash within the BIOS itself. That's the only BIOS flash method I've used and never had a problem. I only avoid the Flashback option because I need to use a mirror to see behind the case and find the right port! If you use EZ Flash, you'll know if the USB stick is working properly when you have to select the BIOS file on the stick.

Despite what Bruce said, I'm still suspicious that 0813 might be locked for allowing earlier versions, only because I still haven't seen anybody say (specifically) that they have tried and succeeded. Can't remember where exactly, but I've now seen 2 or 3 comments where people have experienced errors when trying.

[JohnAb]

Good to know that 0813 can be rolled back. Some posts in this forum seemed to indicate it was not possible.

On some 690 boards like the Hero, for example, it's not possible to roll back prior to BIOS 2004 which was released before Christmas. It depends on the board and BIOS, but sometimes the ability to roll back to an earlier version (via Flashback or EZ Flash 3) is locked. I was wondering if this was the case with 0813.

I'm keeping notes on Intel ME firmware and BIOS versions in this thread:

https://rog.asus.com/forum/showthread.php?131399-Intel-ME-and-BIOS-Updates-General-Advice

In that thread I'm trying to add notes where flashback to an earlier BIOS is not possible, hence my interest.

[iBruceypoo]

Good point John, I shouldn’t be speaking for Hero bios. Every Apex bios that’s not worked out for me I’d had no trouble rolling back to ANY previous Apex bios, so just assumed it was possible with the Hero.

In total, I’ve had (4) Apex experimental bios, not work well, and easily rolled back. Sorry, if I created any confusion*

[Saltgrass]

I finished testing my system with all four sticks and I thought it was fine, but I put it to sleep and it froze with the fans running.

I attempted to rollback to 703, but EZ Flash did not recognize the file and the Bios Flash back checked the drive and the light went back to steady.

Doing a Bios Flashback with 813 worked normally and took about 4 and 1/2 minutes.