Samsung 990 PRO 4TB ($989) vs WD_BLACK SN7100 4TB ($580). $/TB analysis, performance, and use-case recommendations.
Samsung 990 PRO 4TB and WD_BLACK SN7100 4TB are direct competitors — same generation, same capacity. Choose by controller behavior under sustained load, DRAM/HMB cache strategy, and $/TB economics.
Hardware-wise, the Samsung 990 PRO 4TB runs on Samsung's Pascal controller, fabricated on the company's 8nm process. The WD_BLACK SN7100 4TB pairs the SanDisk A101 — a more recent design from the WD/SanDisk lineup.
The cost difference is hard to ignore: 41% per TB (WD_BLACK SN7100 4TB at $145.00/TB versus Samsung 990 PRO 4TB at $247.25/TB). Unless you specifically need the Samsung 990 PRO 4TB's peak performance, the WD_BLACK SN7100 4TB delivers more storage for the money.
Cache architecture differs: Samsung 990 PRO 4TB has DRAM hardware, WD_BLACK SN7100 4TB uses HMB. For OS, gaming, browsing — indistinguishable. For databases, large file ops, or 4K video editing — DRAM has a small but consistent edge.
Heading to a PlayStation 5? Both drives drop into the console's M.2 bay and report identical real-world benchmarks since the PS5 caps storage at PCIe 4.0 speeds. The WD_BLACK SN7100 4TB wins this matchup on $/TB. 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 Samsung 990 PRO 4TB currently sits #6 while the WD_BLACK SN7100 4TB sits #4. Neither cracks the top of the value table, so it's worth glancing at the alternatives below before picking either.
As of October 19, 2026, these tracked drives undercut both the Samsung 990 PRO 4TB and WD_BLACK SN7100 4TB on $/TB:
The Samsung 990 PRO 4TB is the right call if a dedicated DRAM cache chip matter to you. Samsung backs the PRO series with one of the strongest warranty experiences in consumer storage — RMAs typically process within 5 business days globally.
The WD_BLACK SN7100 4TB is the right call if the lower retail price ($580 vs $989), and better $/TB economics ($145.00/TB) matter to you.