Silicon Power UD90 250GB

The Silicon Power UD90 250GB is an entry-level PCIe 4.0 NVMe drive with a DRAM-less design that uses Host Memory Buffer (HMB) to reduce latency for random I/O. The typical reference design pairs a 4-channel Phison PS5021-E21T controller with Micron 176-layer 3D TLC NAND, but the 250GB capacity limits the number of NAND dies and reduces sequential write throughput. The drive emphasizes power efficiency and thermal management, running cool under sustained loads, and Silicon Power has shipped batches with alternate controllers (Maxio MAP1602, Silicon Motion SM2269XT) in some markets.

Key Specifications

• Interface: PCIe Gen 4.0 x4 (NVMe 1.4)
• Controller: Phison PS5021-E21T (subject to variation)
• NAND Type: 3D TLC (typically Micron 176-layer)
• DRAM Cache: None (HMB enabled)
• Sequential Read: 3,900 MB/s
• Sequential Write: 1,800 MB/s
• Physical Traits: Single-sided M.2 2280 PCB; TCG Opal support

Hardware Alternatives

• TeamGroup MP44L: Shares the most direct architectural lineage with the UD90, frequently utilizing the same Phison E21T and Micron NAND reference design
• Corsair MP600 GS: Another E21T-based relative with performance characteristics similar to the UD90 aside from firmware tuning differences
• WD Black SN770: Primary DRAM-less Gen4 competitor; functionally similar though using a different SanDisk controller with stronger random read performance in some comparisons
• Crucial P3 Plus: Commonly cross-shopped with the UD90 but uses QLC NAND while the UD90 uses TLC NAND