Dual BIOS is afail-safe featureavailable on some high-end ASUS models that can help recover corrupted firmware. It’s a technology that introducestwo ROM chipson the motherboard–if the primary BIOS fails, the second one will back you up.
To know whether your ASUS mobo supports Dual BIOS, you may inspect itsuser manual, checkspecificationsonline, or examine the two chipson the board itself. While the recovery should happen automatically, most models also feature aBIOS Switch buttonfor manually shifting between the main and backup BIOSes.
After comprehensive testing on multiple ASUS motherboards (here at our TechNewsToday office), I have presented a simple guide that should help you understand everything about thisdual-hardware protection feature.
Basics to ASUS Dual BIOS
The Dual BIOS feature on ASUS simply refers to havingtwo EEPROM chipson the mainboard. Both store the firmware settings separately and upon failure of the so-called‘Main’BIOS, the secondary/backup chip (that usually stores the factory defaults) comes to your rescue.
Think of it this way–you wereupdating your ASUS BIOSand it was interrupted after a power surge. I understand how panicking it sounds but with the Dual BIOS feature, the primary BIOS gets reflashed automatically or this can even be done manually!
As we know, ASUS motherboards with single BIOS are difficult to recover after achecksum errorand may even require factory repair. On the flip side, those boards with two ROMs offer better security by providing an additional level of recoverythrough the second chip.
Either of them functions even if one gets corrupted, whether it be bad overclocking, improper/interrupted flashing, virus attacks, or physical damage. Clearly, it’s a great security feature forredundancy and fault tolerance.
Checking Dual BIOS Compatibility
If you’re seeking an ASUS mobo, my tip is to keep ‘Dual BIOS’ as your top priority. Recalling my beginner’s mistakes, I once happened to brick a motherboard when there was a power surge when I was flashing a newBIOS version(as it didn’t include a secondary ROM chip or any other BIOS recovery feature).
When test benching various ASUS motherboards at our TNT office, our team has determined the following ROG models that are Dual BIOS-compatible. However, we couldn’t find any PRIME, TUF Gaming, and ProArt boards that support this feature.
While these are some of the verified ones, we certainly have missed out on many models. If you couldn’t find yours in the table above, you may use any one of the below techniques to test for yourself.
From User Manual
The easiest way to identify Dual BIOS compatibility is from your motherboard’s user manual. You can use thephysical handbookor even open up theonline manualto check for theBIOS Switch Button. Below are some of the different sections that should include this feature:
Via Tech Specifications Online
For beginners, looking up the manual might be a daunting task. Nonetheless, the online specification page is certainly another good idea to know whether your board integrates a BIOS Switch Button:
Inspecting the Motherboard Manually
Instead of having to open the user manual or online specifications, you may directly peek into your ASUS motherboard to locate thedual BIOS chip. They might be labeledM_BIOSandB_BIOSrespectively or sometimes do not come labeled at all.
Also, your board should embed aBIOS Switch Button(as shown in the User Manual) along with twoBIOS_LEDs. While the location varies on every model, the appearance should be somewhat similar to the one that I have demonstrated forROG Zenith II Extremebelow.
Switching Between Main and Backup BIOS
As mentioned above, most ASUS boards offer a dedicated button that lets you manually switch between theMainandRecoveryBIOS. All you have to do is toggle the switch but also keep in mind the safety measures. Here’s a step-by-step guide to help you do just that:
Power Down Your PC
The first step involves closing all the running programs andshutting downyour ASUS system. Also,remove the power supply cablefor safety purposes.
Since you’re going to get close to the mainboard, it’s a good idea to press the power button for 10 to 15 seconds to discharge the remaining capacitors andground yourself.
Access the Mainboard
Next,open up the PC’s side panelto access your ASUS motherboard. If you had checked the user manual earlier, you shouldn’t have any difficulties finding the BIOS Switch button.
Press the BIOS Switch Button
Caution:Do not press the switch during an ongoing BIOS update. This may corrupt both the ROM chips.
Once you have located the BIOS Switch button,press it onceand the secondary BIOS should get activated.
If you had encounteredBIOS corruptionor failed update, the recovery process should now start. Otherwise, just its related BIOS settings should be loaded.
Inspect the BIOS LED
When the main BIOS was active, you probablynoticed an orange lightinBIOS_LED1. To verify whether the shift has been successful,check whether theBIOS_LED2is now glowing.
Recovering Failed BIOS Update Using the Backup BIOS
Failed or corrupted BIOS update leads to no boot issues and in some cases, even prevents you fromentering the ASUS BIOS interface. However, that’s the case on mobos with a single ROM chip.
If your motherboard supports Dual BIOS, the recovery processshould kick in automatically. All you have to do isforce shut down your computerandstart it again. Within a minute or so, you should get your system back as if nothing has happened.
In case that didn’t help, you may try the manual method that I’ve been discussing throughout this article. Justswitch to your‘Backup BIOS’and that should do the job.
While Dual BIOS is an excellent way to recover the failed or interrupted update, it’s only available on some high-end boards. If yours do not support it, you can use other recovery methods, like theUSB BIOS FlashbackorASUS Crash-Free BIOSUtility.
Can I Flash My Backup BIOS?
As mentioned earlier, Dual BIOS is a fail-safe feature. Your system primarily utilizes the main BIOS chip and the secondary one justcontains the factory settings. If anything goes wrong, the backup BIOS is flashed to the main one.
While other manufacturers likeGigabyte include the “Also Update Backup BIOS”option when flashing the main BIOS chip, ASUS hasn’t provided any documentation on whether this is possible.
When my team bench-tested on theROG Zenith II Extremeboard, we couldn’tupdate its backup BIOS. Also, we didn’t find anything on its BIOS and user manual too. If you’re in the same boat, try checking your user manual first. I wouldn’t recommend flashing a new version unless you’re 100% sure of what you’re doing.
Additionally, some systems even support firmware features, likeWide Range Protection,Halt On BIOS Defects,Auto Recovery, etc. While this is the case with boards from other manufacturers, I haven’t found such features on ASUS.
