Silicon Power UD90 4000GB

The Silicon Power UD90 4000GB is a mid-range NVMe drive that uses a DRAM-less architecture, typically paired with the Phison PS5021-E21T controller and high-density 3D NAND. It relies on Host Memory Buffer (HMB) to use a portion of system RAM for mapping tables, can saturate PCIe 4.0 x4 during burst workloads, and uses a dynamic pseudo-SLC cache to mask native NAND write speeds. Component sourcing (NAND manufacturer and NAND type) can vary between batches, which may affect sustained write performance. The single-sided PCB design improves compatibility with thin laptops and tight chassis.

Key Specifications

• Interface: PCIe Gen 4.0 x4 (NVMe 1.4)
• Sequential Read/Write: 5000 MB/s / 4500 MB/s
• Controller: Phison PS5021-E21T (Typical)
• NAND Type: 3D NAND (TLC or QLC, batch dependent)
• DRAM Cache: None (HMB Support)
• Form Factor: M.2 2280
• PCB Layout: Single-sided (High compatibility)
• Endurance: Varies by NAND revision (Typical TBW ratings scale with capacity)

Hardware Alternatives

• TeamGroup MP44L: shares architectural similarities and targets the same performance segment using HMB technology
• Corsair MP600 GS: similar DRAM-less mid-range design targeting comparable performance
• Solidigm P41 Plus: another HMB-based mid-range NVMe alternative
• Western Digital WD Blue SN770: offers a similar DRAM-less performance profile
• Lexar NM710: a direct competitor in the same performance class
• Silicon Power XS70: a top-tier alternative (Phison E18 + DRAM) that emphasizes sustained write performance over the UD90's efficiency and thermal management