Packaging

The Drive

The drive uses the M.2 2280 form factor, which makes it 22 mm wide and 80 mm long.


While most other M.2 NVMe SSDs transfer data over the PCI-Express 3.0 x4 interface, the Silicon Power UD90 connects to the host system using PCI-Express 4.0 x4, doubling the theoretical bandwidth.


On the PCB you'll find the controller and four flash chips, a DRAM cache chip is not present.

Chip Component Analysis

The Phison PS5021-E21 is Phison's newest PCI-Express 4.0 controller. It's a cost-optimized model, with four flash channels and support for TLC and QLC NAND. Phison has designed the E21 for DRAM-less operation, and it supports the NVMe 1.4 protocol. The controller itself is fabricated using a 12 nanometer process at TSMC Taiwan.


The four flash chips are Micron 176-layer 3D TLC NAND. Each chip has a capacity of 256 GB.