Magic ASRock B450 BIOS Brings Zen 3 Support to Asus X370 Motherboard

ROG Crosshair Hero VI
ROG Crosshair Hero VI (Image credit: Asus)

No, you didn't misread the headline. A user from the Asus ROG forums (via Reddit) has evidently found a way to enable AMD's Ryzen 5000 (Vermeer) processors on the ROG Crosshair VI — something that wasn't supposed to happen. What is more shocking is that the firmware hails from the ASRock B450 Pro4 R2.0.

AMD initially only wanted Zen 3 processors to work on the latest 500-series motherboards. After a bit of turmoil from the user base, the chipmaker eventually backpedalled and allowed Zen 3 chips to work on 400-series motherboards. However, AMD was firm in its decision to not include 300-series motherboards on the support list.

That didn't stop enthusiasts from modifying official firmwares to enable Zen 3 support. Of course, that meant staying on the same firmware forever and losing out on future features and stability or bug fixes. But if you're running a 300-series chipset with Zen 3, you're probably not worried about such things.

ASRock brought Zen 3 support to the ASRock B450 Pro4 R2.0 with its 4.50 firmware, which you can download from the product page. According to the ROG forum user, the aforementioned firmware version works on the ROG Crosshair VI as well. Apparently, the 4.80 firmware can also enable AMD's Smart Access Memory (SAM) technology on the ROG Crosshair VI for users who only want that feature.

We don't recommend users to flash firmware from one motherboard to a different model since they sport different designs. There's no guarantee that all the features will work, plus you can end up damaging your motherboard. But if you want to give it a shot, the forum user shared the following process:

  • Download the firmware from ASRock's website.
  • Create a bootable DOS flash drive with Rufus.
  • Copy the firmware to the flash drive.
  • Download AFUDOS (a BIOS flash utility) and copy it to the flash drive.
  • Boot from the flash drive and update the BIOS utilizing the "afudos nameofrom.rom /gan" command (/gan forces the BIOS to write despite a mismatch in BIOS codes).

Thus far, there isn't any user feedback on whether the ASRock firmware degrades the system's stability or which features (if any) on the motherboard end up disabled. If you're tempted to try out the hack, do tread with caution. And be sure to share your experience below in our comments. Given the risks, we'd be more inclined to sell an old 300-series board and upgrade to a newer model.

Zhiye Liu
RAM Reviewer and News Editor

Zhiye Liu is a Freelance News Writer at Tom’s Hardware US. Although he loves everything that’s hardware, he has a soft spot for CPUs, GPUs, and RAM.