Compare WD_BLACK SN850X 2TB and Lexar NM790 2TB: prices, speeds, $/TB. Which to buy in July 2026? Full spec breakdown.
Both the WD_BLACK SN850X 2TB and Lexar NM790 2TB sit in the Gen 4 category at 2 TB, so the matchup turns on controller efficiency, cache topology, and current pricing rather than raw class differences.
Hardware-wise, the WD_BLACK SN850X 2TB runs on WD's G2 controller — manufactured by SanDisk and tuned for low-latency gaming workloads. The Lexar NM790 2TB pairs the MaxioTech MAP1602 — a DRAM-less Gen 4 controller dominating the value tier across TeamGroup, Lexar, and others.
There's a modest pricing advantage for the Lexar NM790 2TB: $155.00/TB compared with $174.00/TB. For typical gaming and productivity, this becomes the deciding factor when specs are close.
The WD_BLACK SN850X 2TB carries a dedicated DRAM chip for FTL (Flash Translation Layer) mapping; the Lexar NM790 2TB relies on HMB (Host Memory Buffer), borrowing 64 MB from system RAM. The practical gap shows up only under sustained random write loads.
For PS5 expansion, both are PCIe Gen 4 M.2 2280 drives that meet Sony's minimum spec (7,300 MB/s read). The console can't take advantage of speeds beyond that, so save money by choosing the Lexar NM790 2TB. Heads-up — these are full-length 2280 drives. Steam Deck and most current handhelds require shorter 2230 modules, so check capacity-specific 2230 variants if that's your target platform.
Market context: we track 11 Gen 4 2 TB drives, and by price per terabyte the WD_BLACK SN850X 2TB currently sits #8 while the Lexar NM790 2TB sits #7. Neither is a value leader right now — if $/TB is your priority, check the cheaper alternatives below before committing.
As of July 27, 2026, these tracked drives undercut both the WD_BLACK SN850X 2TB and Lexar NM790 2TB on $/TB:
Pick the WD_BLACK SN850X 2TB if you value a dedicated DRAM cache chip. Among Gen 4 flagships, the SN850X strikes a sweet spot — premium silicon at sub-Samsung pricing, with WD's established RMA process to back it up.
Pick the Lexar NM790 2TB if you value the lower retail price ($310 vs $348), and better $/TB economics ($155.00/TB). The Lexar NM790 2TB wins on $/TB because it pairs DRAM-less MAP1602 silicon with low-margin distribution. Performance is fine for OS and gaming, weaker only on sustained random writes.