Although AMD does not support the PCIe 4.0 standard on Pre-X570 motherboards, Biostar has enabled functionality on four AMD 400 Series motherboards.
Biostar enables PCIe 4.0 connectivity on selected 400 Series motherboards
As with ASUS, Biostar can only offer PCIe 4.0 speeds in the major PCIe x16 and M.2 slots. However, Biostar has not indicated whether the PCIe x16 slot is running at x16 speed or whether it is limited to x8 when PCIe 4.0 is enabled.
While the option to enable PCIe 4.0 may now be available, AMD will eventually disable it in an AGESA microcode update. Basically, if you want PCIe 4.0, you keep the same firmware for the rest of the motherboard’s life and lose any future performance enhancements or bug fixes. This is the price you will pay if you combine a 3000 series Ryzen chip with a 400 series motherboard and expect PCIe 4.0 compatibility.
Biostar has many AMD Series 400 products in its arsenal, but only four will have this capability. The X470-based motherboards include the X470GT8 and X470GTN, while the B450 chipset-based offerings are the B450MH and B450M2. The firmware to activate PCIe 4.0 is available for download on the respective product pages of the motherboards.
After ASUS and Biostar have brought the first pieces onto the market, it will certainly be very interesting to see if other big motherboard manufacturers like ASRock, Gigabyte and MSI will get on the train. We will keep you up to date.