Which is better, WD_BLACK SN8100 4TB or Lexar NM790 4TB? July 2026 side-by-side with prices, specs, and verdict.
Cross-generation comparisons reveal whether you're paying for peak speed or sustained value. WD_BLACK SN8100 4TB vs Lexar NM790 4TB at 4 TB is a perfect lens for that question.
Hardware-wise, the WD_BLACK SN8100 4TB runs on SMI's SM2508 silicon, which became the default Gen 5 controller for power-conscious flagships. The Lexar NM790 4TB pairs the MaxioTech MAP1602 — a DRAM-less Gen 4 controller dominating the value tier across TeamGroup, Lexar, and others.
At a 27% price gap, the WD_BLACK SN8100 4TB needs to be measurably better in your specific use case to justify the spend. For gaming and general PC use, the Lexar NM790 4TB's lower $/TB tilts the value equation decisively in its favor.
On sequential reads the WD_BLACK SN8100 4TB pulls ahead by 7,500 MB/s (14,900 MB/s versus 7,400 MB/s). That matters for moving large files but rarely shows up in game loads.
Write speeds skew toward the WD_BLACK SN8100 4TB: 11,000 MB/s sustained against 6,500 MB/s. Content creators feel this; gamers do not.
WD_BLACK SN8100 4TB bundles a DRAM cache chip; Lexar NM790 4TB is DRAM-less. This sounds like a big deal but reviewers have been arguing for years about whether it actually matters in consumer use. For most workloads, no.
PS5 owners get no measurable benefit from either drive's peak speed because Sony's internal NVMe controller throttles to ~5,500 MB/s; treat WD_BLACK SN8100 4TB and Lexar NM790 4TB as interchangeable here and let price decide. Generational difference matters mainly for sequential-heavy workloads. The WD_BLACK SN8100 4TB's 14,900 MB/s read beats Lexar NM790 4TB's 7,400 on paper, though in practice both feel identical loading games. Video editors will gravitate toward the WD_BLACK SN8100 4TB for its write headroom (11,000 MB/s sustained). Project saves and proxies move faster, which compounds across a workday. 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: the WD_BLACK SN8100 4TB ranks #3 of 6 Gen 5 4 TB drives we track by $/TB, while the Lexar NM790 4TB ranks #1 of 6 Gen 4 4 TB drives. That puts at least one of them near the top of the value table — a reasonable head-to-head to be choosing from.
At $127.50/TB, the Lexar NM790 4TB is already among the cheapest 4 TB drives we track — nothing in this class undercuts it. See the full $/TB ranking.
Lean toward the WD_BLACK SN8100 4TB when meaningfully faster reads (14,900 MB/s), higher sustained writes (11,000 MB/s), and a dedicated DRAM cache chip top your priority list.
Lean toward the Lexar NM790 4TB when the lower retail price ($510 vs $700), and better $/TB economics ($127.50/TB) top your priority list. The Lexar NM790 4TB 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.