Compare WD_BLACK SN7100 4TB and Lexar NM790 4TB: prices, speeds, $/TB. Which to buy in July 2026? Full spec breakdown.
Both the WD_BLACK SN7100 4TB and Lexar NM790 4TB sit in the Gen 4 category at 4 TB, so the matchup turns on controller efficiency, cache topology, and current pricing rather than raw class differences.
Hardware-wise, the WD_BLACK SN7100 4TB runs on an A101 controller that replaced the older WD designs in the SN7100 generation. The Lexar NM790 4TB 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 4TB: $127.50/TB compared with $142.50/TB. For typical gaming and productivity, this becomes the deciding factor when specs are close.
For PS5 expansion, both are PCIe Gen 4 M.2 2280 drives that meet Sony's minimum spec (7,000 MB/s read). The console can't take advantage of speeds beyond that, so save money by choosing the Lexar NM790 4TB. 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 6 Gen 4 4 TB drives, and by price per terabyte the WD_BLACK SN7100 4TB currently sits #5 while the Lexar NM790 4TB sits #1. 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.
The WD_BLACK SN7100 4TB fits buyers who prefer its specific performance profile or have brand preference for WD.
Pick the Lexar NM790 4TB if you value the lower retail price ($510 vs $570), and better $/TB economics ($127.50/TB). 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.