The RTL9210B is distinct for its "dual-protocol" support, allowing it to interface with both NVMe (PCIe) NGFF (SATA)

Key Features

is a 68-pin QFN "green" package controller that integrates several key power and interface components directly onto the silicon.

Conclusion

Complete Guide to the RTL9210B Datasheet (2021): Pinouts, Specs, and Design Insights

In practice, 2021 enclosures using the RTL9210B ran significantly cooler than ASM2362 designs, making them suitable for high-performance NVMe drives without active cooling.