Gigabyte releases new firmware with AMD's revised AGESA 126.96.36.199 ABB microcode for the brand's AMD 300-and 400-series motherboards. The latest microcode addresses a couple of issues with Ryzen 3000-series processors, but it also removes PCIe 4.0 functionality.
By now, it should be common knowledge that AMD doesn't intend to enable PCIe 4.0 on pre-X570 motherboards due to the physical limitations. However, motherboard vendors, including Asus, Biostar, and Gigabyte previously enabled the feature against AMD's wishes. It seems that our luck has finally run out.
The changelog for the latest firmware for Gigabyte motherboards clearly specifies that the PCIe 4.0 option has been removed. The change is effective as of the F42a BIOS and affects all Gigabyte 300-and 400-series products starting from the flagship X470 motherboards down to the budget A320 offerings.
1. Update AGESA 188.8.131.52 ABB2. Improve Destiny 2 gaming compatibility 3. Remove PCIe Gen4 support when using a 3rd Gen Ryzen (Matisse) CPU
Either the AGESA 184.108.40.206 ABB microcode is the culprit here, or Gigabyte disabled PCIe 4.0 functionality out of its own free will. For now, it's impossible to tell because Gigabyte is the only motherboard manufacturer to deploy new firmware with the updated microcode. Once other vendors begin releasing new firmwares for their products, we'll be able to find out whether it was AMD or Gigabyte that pulled the trigger.
One way or the other, pre-X570 motherboard owners are certainly at a very important crossroad right now. Upgrading implicates losing the PCIe 4.0 feature while not upgrading means losing out on a lot, such as new features, bug fixes, or even performance enhancements.