Lexar NM990 4000GB

SSD Description

The Lexar NM990 4000GB is a flagship PCIe 5.0 NVMe M.2 drive built around the Phison PS5026-E26 client controller, an 8-channel design on a 12nm process with dedicated LPDDR4 DRAM for mapping table management. The controller is paired with high-density 232-layer 3D TLC NAND operating at interface speeds of up to 2400 MT/s to maximize utilization of Gen5 x4 lanes, benefiting large-file sequential transfers and DirectStorage-aware applications. The hardware combination has high thermal density: the E26 controller can sustain extreme throughput but generates significant heat, so the drive requires a substantial heatsink or active cooling to avoid rapid thermal throttling. Users should verify motherboard M.2 heat spreader contact pressure, as the controller will reduce clock speeds if core temperatures exceed typical thresholds (around 80°C and above).

Key Specifications

• Capacity: 4000GB
• Interface: PCIe 5.0 x4 / NVMe 2.0
• Controller: Phison PS5026-E26 (ARM Cortex-R5 architecture)
• NAND Configuration: 232-Layer 3D TLC
• NAND Interface Speed: up to 2400 MT/s
• Max Sequential Read: 14,000 MB/s
• Max Sequential Write: 11,000 MB/s
• DRAM Cache: Yes (LPDDR4/4X)
• Features: Microsoft DirectStorage optimized, LDPC ECC, SLC Caching architecture

Hardware Alternatives

• Crucial T705 4000GB and Corsair MP700 PRO SE 4000GB: Direct hardware relatives sharing the same Phison E26 controller and 232-layer NAND reference design; differences are mainly firmware tuning and stock cooling solutions.
• Seagate FireCuda 540: Utilizes the same E26 controller architecture but often ships with firmware tuned for slightly lower peak speeds (around 10,000 MB/s) in exchange for different endurance ratings.
• Samsung 990 PRO 4000GB: Limited to the PCIe 4.0 interface (reducing maximum sequential throughput) but competes strongly in random I/O performance and power efficiency.