Lexar NQ790 4000GB

SSD Description

The Lexar NQ790 4000GB utilizes a DRAM-less architecture built around the Maxio MAP1602 controller, a four-channel design commonly associated with high-efficiency PCIe 4.0 implementations. To compensate for the lack of onboard DRAM, the drive employs Host Memory Buffer (HMB) technology, utilizing a small portion of system RAM for logical-to-physical address mapping. The 4TB capacity is achieved using high-density 3D QLC NAND (typically YMTC 232-layer Xtacking 3.0), allowing the drive to maintain a single-sided PCB profile while reaching bus-saturating burst speeds. Performance analysis indicates that while the NQ790 offers burst throughput comparable to high-end TLC drives, its sustained write performance is dictated by the underlying QLC media; once the dynamic pseudo-SLC cache on the 4TB model is exhausted, write speeds drop significantly to native NAND speeds. The drive is frequently noted for its power efficiency and low thermal output, making it suitable for laptops and enclosures with limited airflow.

Key Specifications

• Capacity: 4000GB
• Interface: PCIe 4.0 x4 (NVMe 1.4)
• Controller: Maxio MAP1602 (4-Channel, ARM Cortex-R5)
• NAND Type: 3D QLC (typically YMTC 232-layer Xtacking 3.0)
• Sequential Read/Write: 7000 MB/s / 6000 MB/s
• DRAM Cache: None (HMB Support)
• Physical Layout: M.2 2280, Single-sided PCB

Hardware Alternatives

• Lexar NM790 4000GB: The direct sibling to the NQ790; uses the identical Maxio MAP1602 controller but pairs it with 3D TLC NAND rather than QLC, offering superior endurance and sustained write performance.
• HP FX700 4000GB: Often shares the same controller and QLC NAND configuration, effectively acting as a hardware clone in many regions.
• Crucial P3 Plus 4000GB: Utilizes the Phison E21T controller paired with Micron QLC NAND; targets a lower peak throughput tier compared to the NQ790.
• Solidigm P41 Plus: Features the Silicon Motion SM2269XT controller and, like the NQ790, relies on QLC media and HMB, though it targets a lower throughput tier.