Datasheet | Rtl9210b
: Ensure your M.2 SSD is either M-Key (NVMe) or B+M Key (NVMe or SATA). The bridge does not typically support older mSATA or M.2 PCIe AHCI drives.
PCIe Gen3 x2 (up to 16Gbps bandwidth internally). SATA Mode: SATA Gen3 (up to 6Gbps bandwidth). rtl9210b datasheet