WD Triton MP28

The WD Triton MP28 (full designation: 20-82-00705-A2) is Western Digital's in-house NVMe controller used in the WD Blue SN500, SanDisk Extreme Pro NVMe (2018), and the OEM PC SN730. It is a triple-core ARM 32-bit Cortex-R5 design on TSMC's 28nm process, with 8 flash channels running at 800 MT/s and 4 chip-enables per channel. The Triton MP28 is DRAM-equipped, unlike the later Polaris-generation controllers.

The three Cortex-R5 cores have a defined division of labour: one manages host interface operations, one handles read operations, and one processes writes. The controller includes hardware LDPC (Low-Density Parity-Check) error correction tailored for Western Digital's 3D NAND, and supports Western Digital's nCache 3.0 dynamic pseudo-SLC caching: incoming data is written to SLC blocks for burst performance, then relocated to TLC during idle periods.

The 8-channel configuration was used in the SanDisk Extreme Pro NVMe (2018) and the PC SN730 (OEM), while the WD Blue SN500 uses a 4-channel variant of the same controller for a lower-cost positioning. The PC SN730 pairs the Triton MP28 with 96-layer BiCS4 3D TLC NAND running at 667–800 MT/s, an upgrade from the 64-layer BiCS3 used in earlier WD designs.