As rumored and detailed earlier, the AMD A520 chipset completely lacks PCIe Gen 4 support and lacks overclocking or dual graphics support. When compared to the previously available A320 chipset, the A520 has PCIe 3.0 support as well as adds two more PCIe lanes from the chipset.
Specification-wise, the A520 chipset brings PCIe Gen 3 x16 as the main PEG slot with 6 lanes from PCIe downstream (while B550 offers eight lanes). As noted, and unlike the B550, the A520 chipset runs storage over PCIe Gen3 x4. It also offers a total of five 10Gbps USB ports, two 5Gbps USB, and six Hi-Speed USB 480 ports, two SATA 6Gbps, and motherboard makers can pick between x4 NVMe Gen 3, two additional SATA + x2 NVMe Gen 3, or 2x2 NVMe Gen 3 ports.
Currently and as far as we are aware, the A520-based motherboards only support Ryzen 3000 Matisse desktop processors, and there is planned support for 4000G Renoir CPUs when they launch.
There are plenty of motherboard makers that have announced their own motherboards, and we expect them on retail/e-tail shelves soon with a price set well below $100, as this is an entry-level chipset.