How to Update BIOS Without CPU? – 3 Critical Steps

Do you have a newer generation processor that requires a BIOS update to be supported on your motherboard? Given the scenario, you’re probably wondering how to update BIOS without CPU. The first question you should be trying to answer, however, is if your motherboard supports this feature.

Understand that majority of motherboards do not support flashing the BIOS without a processor and memory module mounted. Only a limited number of motherboard models support this functionality. While you can find a couple of newer generation motherboard models with this feature within the $100-$150 price range, most come with premium price tags as they are high-end/top-of-the-line models.

This whole scenario of needing to update the BIOS without a CPU and RAM installed wasn’t as prevalent in the earlier half of the decade as it has been in recent years. It’s mostly due to the influx of recent processor releases that are designed to be supported by the chipsets in prior motherboard releases.

Be it an upgrade or a sorted assembly, it’s just a whole lot cheaper to couple a newer generation processor with an older, compatible motherboard than the latest or higher-end one. The only caveat is the BIOS update that will allow the older motherboard to support the newer chip.

How Do I Know if My Motherboard Supports USB BIOS Flashback?

how to update bios without CPU
ASUS ROG STrix B550-F Mobo showing BIOS Flashback on the left side of the I/O panel

A simple physical inspection can tell you whether your motherboard supports this feature. Most of the time, you’ll only need to look at the rear I/O and their labels, if there are any, to ascertain this. Some motherboards have the BIOS flashback button beside one of the USB port columns in the rear I/O while others have a more pronounced button somewhere in the motherboard.

Of course, when in doubt, you should just look at the manual. It should list all of your motherboard’s features including the BIOS flashback button’s location.

Moreover, the owner’s manual also usually has illustrated instructions on how to properly perform certain tasks involving the motherboard including flashing the bios.

Motherboard manufacturers have their own naming schemes for this feature. Asus calls it the USB BIOS Flashback while Gigabyte named it Q-Flash/Q-Flash+. MSI has M-Flash while Asrock simply has BIOS Flashback. Regardless of the naming scheme, however, they all do the same thing; allow the user to flash the BIOS using a USB thumb drive, without the need for a CPU and memory modules.

If you purchased your motherboard online, you might want to revisit the product listing. USB BIOS Flashback/Q-Flash+/M-Flash/Bios Flashback or other naming schemes from other brands for this specific feature is usually a very good selling point and is highlighted within the listing’s overview, the FAQs, and/or specifications.

The review section for the product listing is a good place to get confirmation if you’re still in doubt.

Intel motherboards have had this feature for a while now. In fact, Asus first released the USB BIOS Flashback feature back in 2010 with the introduction of their RAMPAGE III series for the X58 Chipset.

It wasn’t until the recent years that such feature was packaged with AMD motherboards – only 2 manufacturers have done so at the time of writing.

While every motherboard model with this feature can’t possibly be covered in this post, if you’re looking for AMD AM4 motherboards with a BIOS Flashback feature then it’ll have to be either Asus (Crosshair VI Extreme X370, Crosshair VI Hero X370, Crosshair VI Hero X370 (Wi-Fi AC), Crosshair VII Hero X470 and Crosshair VII Hero X470 (Wi-Fi)) or MSI (X370 Gaming M7 ACK, X370 XPower Gaming Titanium, X470 Gaming M7 AC, X470 Gaming Pro Carbon, B450 Gaming Pro Carbon AC, B450 Tomahawk, B450 Gaming Plus, B450-A Pro, B450M Gaming Plus).

Also Read:

How to Update BIOS Without CPU?

The steps on flashing the BIOS are, for the most part, almost the same across all motherboard brands. The only real difference is that each brand has its own unique naming scheme and file extensions for the BIOS files.

There are three critical steps in updating the BIOS

  1. Preparing the Thumb Drive
  2. Preparing the BIOS files
  3. Flashing the BIOS

Step 1: Preparing the Thumb Drive

USB drive
A spare thumb drive is essential for BIOS update.

The BIOS files’ size shouldn’t be an issue. In fact, they are just a few megabytes. Any thumb drive above a gigabyte in storage capacity should do the job just fine. Make sure to format them as instructed below.

Note: Manufacturers suggest a single-sector USB 2.0 device for stability.

  1. Proceed to the disk management/disk utility window and choose to format the drive. Make sure it only has a single sector.
  2. For the file system, choose FAT32. If it prompts for a partitioning scheme, choose Master Boot Record (MBR).
  3. Check the quick format option if it’s available and initiate the formatting process. It should prompt when it’s done, which should take just a few seconds if you ticked the quick format option.

Step 2: Preparing the BIOS Files

Each of the established motherboard brands has its own portal from which the BIOS updates can be downloaded. Look up the motherboard model in the manufacturer’s portal. The product page should have a dedicated section for all the software files, including the BIOS updates, related to that specific model.

  1. Download the files/zip file. For Asus, the BIOS updates are usually under the Drivers and Tools section. Gigabyte, Asrock and MSI have them under the Support section of the product page. Select the BIOS version you intended to use, which should be any version higher than the one you currently have installed on your motherboard – the newest available when possible.

Do note that in some cases, a specific BIOS version will list a prior version as a requisite for its installation. In cases such as this, you’ll have to flash the BIOS at least two times.

  1. Extract and rename the file/files. The downloaded files are usually zipped and hence, you’ll need to extract them. Once extracted, you should be able to see access and edit the contents.

For MSI, you’ll need to rename the file as “MSI.ROM”. Remember that it needs to be uppercase. The accompanying text file should also have instructions.

For Asus, there should be an accompanying renaming tool packed within the zip file. Click on the tool and it should rename the BIOS file. The file extension should be “.CAP”.

For Gigabyte, you actually don’t need to do any file renaming after extracting.

  1. Copy the file to the thumb drive and eject.

Step 3: Flashing the BIOS

flashing bios
Every motherboard has different steps on how to flash BIOS

Ideally, this should be done before assembling the PC; while the motherboard has yet to be mounted to the case and the CPU, RAM and GPU have not been installed. All that needed is for the 24-pin power connector to be plugged in. Make sure that the PSU itself is connected to a power source.

  1. Plug the thumb drive to the intended USB port. The manual details which USB port is meant for USB flashback. In most cases, it should be the USB port closest to the BIOS flashback button.
  2. Turn on the motherboard.
  3. Press the BIOS flashback button for 3 seconds before letting go. You’ll know that the flashing process started once the flashback LED starts blinking. If your thumb drive has an LED, it should also start blinking. The whole process will take less than 5 minutes.
  4. The LEDs will stop blinking once the flashing is done. Turn off the motherboard/PSU and eject the thumb drive.

To assess whether the process is successful or unsuccessful, the system will need to post, which means that the PC in its entirety will need to be assembled.

Also Read: How to Enable Motherboard HDMI?


Bear in mind that flashing/updating the BIOS carries the risk of completely ruining the motherboard; turning it into nothing more than a brick. Make sure that you’re secured from power outages during the flashing process.

Also, make sure that you have the correct BIOS file. While the motherboard brands may have an established system in place for their employees, errors and lapses do occur from time to time. For instance, Gigabyte’s download link for BIOS version F32 of an AORUS motherboard actually initiates a download for BIOS version F40 of that motherboard.

The above-mentioned scenario may seem harmless but it can actually lead to catastrophe given that some versions require specific preceding versions.

Only flash a BIOS when you really understand what you’re doing.


The process of how to update BIOS without CPU is quite simple and easy to follow. As long as the motherboard supports the feature, everything else is quite straightforward. As long as you bear in mind the key points for preparing the thumb drive and the BIOS files, the flashing should be a breeze.

However, while the process is not convoluted, the situation is. When you can, especially if you do not know what you’re doing, avoid flashing/updating the BIOS. A better alternative would be to have someone, preferably someone with experience, do it for you granted that the charges do not eclipse the cost of the motherboard.

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