Compare Samsung 990 PRO 4TB and WD_BLACK SN7100 4TB: prices, speeds, $/TB. Which to buy in May 2026? Full spec breakdown.
Both the Samsung 990 PRO 4TB and WD_BLACK SN7100 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 Samsung 990 PRO 4TB runs on Samsung's 8nm Pascal controller, the silicon powering the 990 PRO line. The WD_BLACK SN7100 4TB pairs SanDisk's A101 controller, used in newer WD_BLACK SKUs after the SanDisk spinoff.
There's a modest pricing advantage for the WD_BLACK SN7100 4TB: $79.75/TB compared with $97.25/TB. For typical gaming and productivity, this becomes the deciding factor when specs are close.
The Samsung 990 PRO 4TB 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.
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. Both drives use the 2280 form factor, which is too long for Steam Deck or ROG Ally — you'd need a 2230 variant if either manufacturer offers one, or a dedicated handheld-format drive instead.
Pick the Samsung 990 PRO 4TB if you value a dedicated DRAM cache chip. Samsung's PRO line has the longest track record for firmware reliability — over a decade of consumer SSDs with global RMA support.
Pick the WD_BLACK SN7100 4TB if you value the lower retail price ($319 vs $389), and better $/TB economics ($79.75/TB).