According to Tom’s Hardware, it looks like Gigabyte is pulling support for PCIe 4.0 from any pre-X570 motherboards.
It seems that AMD’s revised AGESA 126.96.36.199 ABB microcode for both the 300 and 400-class motherboards not only addressed a few issues for their latest 3000-series Ryzen CPUs, but also removed support for PCIe 4.0.
Tom’s Hardware notes that the change log for the firmware update specifically makes mention of removal of PCIe 4.0 option as of the F42a BIOS. This affects any motherboard from X470 down to A320.
AMD’s Ryzen 3000-series is the first class of CPUs to support PCIe 4.0. We liked the Ryzen 3000-series, with Hardware Editor Chris Coke saying the following about the Ryzen 3700x and 3900x,
“For pure gaming performance, Intel still has a slight lead - but if you’re doing anything else, like streaming or recording gameplay at the same time, or also use your PC for creative work like photo and video editing, AMD is the clear best choice. The price to performance ratio simply cannot be beat and deserves our highest recommendation.”