B550 series motherboards are compatible with current AMD Ryzen 3000 series processors and next-gen Ryzen processors. Premium B550 motherboards that feature strong VRM cooling through solid power and thermal design could even support flagship models like the Ryzen 9 3950X.

The biggest difference between B450 & B550 is the support for PCIe 4.0. B550 is PCIe 4.0 capable; however B450 only supports PCIe 3.0.

PCIe is the slot that is widely used by graphic cards, wifi cards or other expansion components. PCIe 4.0 is the next-gen version of PCIe 3.0 which is 2x faster in speed. Expansion slots with PCIe 4.0 bandwidth (like the PCIe 4.0 x16 slot or M.2 slot) could be found on motherboards which support PCIe 4.0, like the B550 or X570 platform.

Two main reasons: the chipset cost and feature set. The cost of B550 chipset is much higher than B450 but it could support PCIe 4.0, which is not available on B450.

The exterior, power phase, thermal module, and connectivity would be different between GIGABYTE & AORUS B550 motherboards. If you’re looking for a budget-friendly B550 motherboard, you could go for the GIGABYTE B550; if you will pair a higher-tier Ryzen processor like Ryzen 7 or even Ryzen 9, you could go for an AORUS B550 motherboard.