Side-by-side: Samsung 990 PRO 4TB ($825) vs WD_BLACK SN850X 4TB ($535). $/TB winner, specs, real-world picks for July 2026.
Gen 4 at 4 TB is one of the most contested SSD segments in 2026, and Samsung 990 PRO 4TB versus WD_BLACK SN850X 4TB captures that competition well. The decision rarely comes down to peak speeds — both drives saturate typical workloads.
Hardware-wise, the Samsung 990 PRO 4TB runs on Samsung's 8nm Pascal controller, the silicon powering the 990 PRO line. The WD_BLACK SN850X 4TB pairs the proprietary WD G2 silicon, optimized for the WD_BLACK line.
Money matters here — $133.75/TB on the WD_BLACK SN850X 4TB versus $206.25/TB on the Samsung 990 PRO 4TB. That's enough of a spread that for budget-conscious builders, the WD_BLACK SN850X 4TB becomes the default unless reviews of your specific workload prefer the Samsung 990 PRO 4TB.
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 SN850X 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.
How do these two fit the wider Gen 4 4 TB field? Out of 6 tracked drives, the Samsung 990 PRO 4TB is #6 on $/TB and the WD_BLACK SN850X 4TB is #4. Neither cracks the top of the value table, so it's worth glancing at the alternatives below before picking either.
As of July 27, 2026, these tracked drives undercut both the Samsung 990 PRO 4TB and WD_BLACK SN850X 4TB on $/TB:
Samsung's PRO line has the longest track record for firmware reliability — over a decade of consumer SSDs with global RMA support.
Go with the WD_BLACK SN850X 4TB for the lower retail price ($535 vs $825), and better $/TB economics ($133.75/TB). WD_BLACK's SN850X earned its reputation through consistent sustained performance under gaming workloads — fewer micro-stutters during open-world streaming than budget alternatives.