Both are PCIe Gen4 x4 NVMe drives from the current generation of each maker's flagship consumer line. At 3 matched capacities where both are currently in stock, the average gap is +5.2% ($/GB, Samsung relative to WD). This page compares price and published specification only - it does not test performance.
Updated
This page compares live price at matched capacities and each maker's own published specification, labelled as a maker claim wherever it appears. It does not test either drive and makes no speed or performance ranking - see our Gen4-vs-Gen5 page for the cited, published measurements this cluster relies on for performance context, none of which tested this exact pairing.
Comparing an average $/GB across every SN850X listing against every 990 Pro listing would measure the two brands' capacity mix as much as it measures the price gap between them - if one brand happens to have more small-capacity listings in stock and the other more large-capacity ones, a blended average moves for reasons that have nothing to do with which drive is the better buy at a given size. Matching capacity first, then comparing price, is the same discipline this site applies to every cross-brand comparison it publishes, because a $/GB figure that mixes capacities answers a question nobody asked.
Both drives sit at the top of their respective maker's current consumer NVMe lineup - WD's Black series is its gaming-and-creator-focused consumer line, and Samsung's Pro series occupies the equivalent position in Samsung's own current catalogue. Both ship in bare and PS5-labelled heatsink variants from their makers, and both are widely stocked across the retail channel we track, which is part of why a matched-capacity comparison between them is possible at as many capacities as it is - thinner-stocked model lines frequently fail to clear the in-stock-on-both-sides bar this page requires before it will show a row at all.
That wide stock coverage is itself informative: both lines are established enough, and sold through enough of the retail channel we track, that a matched-capacity price comparison is meaningful rather than a snapshot of one seller's momentary listing. Neither drive is a niche or discontinued part being compared against a mainstream one - both remain current, actively-restocked products from their makers as of this page's freshness date above, which is part of why we picked this specific pairing over a less evenly-matched one for this cluster's third compare page.
Read the percentage column as what it is: how much more (or less) the cheapest currently in-stock 990 Pro costs per gigabyte than the cheapest currently in-stock SN850X, at the same capacity, right now. It is not a prediction of tomorrow's gap, and a positive number at one capacity does not guarantee the same sign at another - stock, promotions and individual seller pricing all move independently at each size. If you are deciding between the two for an upcoming build, we would treat this table as the fastest way to check today's actual number rather than rely on either brand's general reputation for value, since that reputation can lag what the live market is actually doing on a given day.
| Capacity | WD SN850X | Samsung 990 Pro | Gap |
|---|---|---|---|
| 1TB | $199.99 ($0.200/GB) | $216.74 ($0.217/GB) | +8.5% |
| 2TB | $398.00 ($0.199/GB) | $354.45 ($0.177/GB) | -11.1% |
| 4TB | $549.99 ($0.137/GB) | $649.99 ($0.162/GB) | +18.2% |
WD SN850X has live stock at 8TB with no matching in-stock 990 Pro capacity.
This is one of three matched-capacity SSD compares this site currently publishes, alongside a Fanxiang-vs-990-Pro budget comparison and a Samsung-internal 990-Pro-vs-9100-Pro Gen4-vs-Gen5 comparison. Together they cover three different buying questions - budget brand against an established one, one generation against the next from the same maker, and here, two established flagship lines against each other - each using the identical matched-capacity method so the numbers are comparable in method even when the products are not.
Two things would make this comparison more complete: a published, head-to-head game-load test of these two exact drives, and a directly comparable warranty/TBW figure sourced from both makers' current datasheets. We have neither this session, and we would rather say so plainly than fill either gap with a plausible-sounding but unverified number. If either becomes available, this page is the place it would be added.
Samsung 990 Pro vs 9100 Pro (Gen4 vs Gen5, matched capacity) · Gen4 vs Gen5, the cited case · Gaming SSD hub
It depends on capacity and changes with stock - see the matched table above for today's live figure at each capacity both sides hold in stock. This is a price comparison only.
We could not locate a published test that specifically pairs the WD Black SN850X against the Samsung 990 Pro in game-load testing this session. Our general Gen4-vs-Gen5 measurements page cites tests involving other specific drives (a Samsung 980 Pro, a Crucial T700, a Seagate FireCuda 540) - both the SN850X and 990 Pro are Gen4 drives from the same generation as the drives in that testing, but we are not attributing those specific results to this specific pairing.
Yes - both the WD Black SN850X and the Samsung 990 Pro are PCIe Gen4 x4 NVMe drives, per our own catalogued generation data for each. This is a same-generation, cross-brand comparison, not a Gen4-vs-Gen5 one.
Not answered here. This page carries no benchmark or speed ranking of our own - only live price at matched capacities and each maker's own published specification, labelled as a maker claim wherever it appears.
Both WD and Samsung have shipped PS5-labelled variants of these drives (typically bundled with a heatsink) in addition to the bare desktop versions compared here. Check the specific listing's own title and Sony's own published PS5 M.2 SSD requirement - see our PS5 SSD hub.
That's a reasonable read of the evidence on this cluster: published testing elsewhere in our Gen4-vs-Gen5 coverage found minimal real-world gaming difference between comparably-specced drives of the same generation, which is what these two are. The live price delta above is the number we'd weight most heavily absent a head-to-head test of this specific pairing.
Both makers sell bare and heatsink-equipped variants depending on the listing - check the specific listing's own title, since the matched table above draws from whichever variant is cheapest in stock at each capacity and does not distinguish bare from heatsink-equipped rows separately. See our thermals page for why that distinction matters for Gen5 specifically; both drives compared here are Gen4.
We have not sourced a current, directly-comparable warranty or TBW figure for both drives this session, and we would rather omit the comparison than present a half-verified one as settled. Check each manufacturer's own current product page for their stated warranty term and endurance rating before buying.