Compare Samsung 990 PRO 2TB and WD_BLACK SN7100 4TB: prices, speeds, $/TB. Which to buy in July 2026? Full spec breakdown.
Both run on Gen 4 hardware but at different capacities: 2 TB for the Samsung 990 PRO 2TB versus 4 TB for the WD_BLACK SN7100 4TB. Whether the larger drive's $/TB advantage justifies the higher upfront cost depends on how much you actually need.
Hardware-wise, the Samsung 990 PRO 2TB 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.
Price separates these two meaningfully. The WD_BLACK SN7100 4TB costs $142.50/TB versus $194.00/TB for the Samsung 990 PRO 2TB — a 27% premium that needs justification in real benchmarks, not just spec-sheet bragging.
The Samsung 990 PRO 2TB carries a dedicated DRAM chip for FTL (Flash Translation Layer) mapping; the WD_BLACK SN7100 4TB relies on HMB (Host Memory Buffer), borrowing 64 MB from system RAM. The practical gap shows up only under sustained random write loads.
Endurance leans toward the WD_BLACK SN7100 4TB at 2,400 TBW (versus 1,200 TBW for the Samsung 990 PRO 2TB). For most consumers this never becomes a real concern — 600 TBW lasts a decade of normal writes — but heavy daily writers should weight it.
For PlayStation 5 builds, the console's internal M.2 slot tops out around 5,500 MB/s sustained, so both Samsung 990 PRO 2TB and WD_BLACK SN7100 4TB hit the same wall — pick whichever is cheaper at the moment you buy. 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 Samsung 990 PRO 2TB ranks #10 of 11 Gen 4 2 TB drives we track by $/TB, while the WD_BLACK SN7100 4TB ranks #5 of 6 Gen 4 4 TB drives. Neither is a value leader right now — if $/TB is your priority, check the cheaper alternatives below before committing.
Pick the Samsung 990 PRO 2TB if you value the lower retail price ($388 vs $570), and a dedicated DRAM cache chip. Samsung backs the PRO series with one of the strongest warranty experiences in consumer storage — RMAs typically process within 5 business days globally.
Pick the WD_BLACK SN7100 4TB if you value better $/TB economics ($142.50/TB), and a higher TBW endurance rating (2,400 TBW).