WD Polaris MP16+

The WD Polaris MP16+ (full designation: 20-82-10081-A1) is Western Digital's in-house NVMe controller used in the WD Black SN770, WD Blue SN570, and WD Blue SN580. It is a direct successor to the Polaris MP16, sharing the same triple-core ARM 32-bit Cortex-R architecture on TSMC's 16nm FinFET process, but with PCIe 4.0 x4 support and faster flash channels running at 1,600 MT/s versus the MP16's 1,200 MT/s.

Like the MP16, the MP16+ is a DRAM-less controller using Host Memory Buffer (HMB). It has 4 flash channels with 4 chip-enables per channel. The SN770 and SN580 are the mainstream PCIe 4.0 tier in WD's lineup, with the MP16+ delivering competitive sequential throughput at a lower cost than DRAM-equipped designs. The SanDisk Extreme M.2 NVMe SSD (2023) also uses the MP16+ under the SanDisk brand.