Retailer photo of Western Digital WD_Black SN850X 4TB. View this offer in Where to buy
Western Digital · SSD · PCIe 4.0
Western Digital WD_Black SN850X 4TB
Works well for: System Drive, Game & File Storage, Heavy Creative Work
Trade-offs: Current price sits $135 above the strong-value threshold (~$515)
- Capacity
- 4 TB
- Interface
- M.2 PCIe 4.0 x4
- Sequential read
- 7300 MB/s
- Sequential write
- 6600 MB/s
- Endurance
- 2400 TBW
- Form factor
- M.2-2280
Move a slider and the page re-scores this product against the same market frame.
Is this a good buy today?
Market confidence: MediumAt $650 the Western Digital WD_Black SN850X 4TB is priced 9% below its $714 representative market level. Crucial T705 2TB currently does the same job for $350.
Worth putting side by side:Compare with Crucial T705 2TB
Prices & availability
Where to buy the Western Digital WD_Black SN850X 4TB
Compare the offers we track for this model, across variants and retailers.
4 tracked offers · 3 retailers
| Variant | Store | Condition | Price (snapshot) | Value · Balanced | Checked | Offer link |
|---|---|---|---|---|---|---|
| Western Digital WD_Black SN850X 4TB | CentralComputer | New | $650 | 68 | 2026-09-27 | View offer → |
| Western Digital WD_Black SN850X 4TB | Newegg | New | $689 | 65 | 2026-09-27 | View offer → |
| Western Digital WD_Black SN850X 4TB (Heatsink) | Newegg | New | $739 | 62 | 2026-09-27 | View offer → |
| Western Digital WD_Black SN850X 4TB | B&H | New | $1,000 | 50 | 2026-09-27 | View offer → |
| Western Digital WD_Black SN850X 4TBMultiple variants available | Amazon Affiliate | Varies | Find on Amazon | Not tracked | No price snapshot | Find on Amazon → |
Prices are dated snapshots, not live quotes — confirm the final price at the store. New, refurbished and used offers are listed separately; used offers carry warranty and seller risk.
Where it stands in the field
Two different questions, side by side. Performance compares what the hardware can do; Value compares what that capability costs at today’s price. A product can rank high on one and low on the other — that gap is the point.
Performance Balanced
How much it can do. Price plays no part in this ranking.
#78 of 385 graded solid state drives
- #75 SeagateSeagate FireCuda 530R 1TB 50
- #76 Western DigitalWestern Digital Black SN850X 8TB 49
- #77 Western DigitalWestern Digital Black SN850X 8TB 49
- #78 Western DigitalWestern Digital WD_Black SN850X 4TB 49
- #79 Western DigitalWestern Digital Black SN850X 4TB 49
- #80 SeagateSeagate FireCuda 530 4TB 49
- #81 Western DigitalWestern Digital SN850P 4TB 49
Value Balanced
How much of that you get for today’s price.
#52 of 385 currently priced solid state drives
- #49 SamsungSamsung 9100 PRO 8TB 68
- #50 KingstonKingston NV3 2TB 68
- #51 TeamGroupTeamGroup FORCE G70 PRO Aluminum 4TB 68
- #52 Western DigitalWestern Digital WD_Black SN850X 4TB 68
- #53 Western DigitalWestern Digital Black SN850X 2TB 67
- #54 ADATAADATA XPG GAMMIX S70 Blade 2TB 67
- #55 KingstonKingston NV3 4TB 67
Performance System Drive
How much it can do. Price plays no part in this ranking.
#78 of 385 graded solid state drives
- #75 SeagateSeagate FireCuda 530R 1TB 50
- #76 Western DigitalWestern Digital Black SN850X 8TB 49
- #77 Western DigitalWestern Digital Black SN850X 8TB 49
- #78 Western DigitalWestern Digital WD_Black SN850X 4TB 49
- #79 Western DigitalWestern Digital Black SN850X 4TB 49
- #80 SeagateSeagate FireCuda 530 4TB 49
- #81 Western DigitalWestern Digital SN850P 4TB 49
Value System Drive
How much of that you get for today’s price.
#84 of 331 currently priced solid state drives
- #81 Western DigitalWestern Digital SN850P 2TB 28
- #82 ADATAADATA LEGEND 960 MAX 1TB 28
- #83 Western DigitalWestern Digital Blue SN5100 500GB 28
- #84 Western DigitalWestern Digital WD_Black SN850X 4TB 28
- #85 CrucialCrucial T500 2TB 28
- #86 PatriotPatriot Viper VP4300 Lite 4TB 28
- #87 MSIMSI SPATIUM M480 PRO 4TB 28
Performance Game
How much it can do. Price plays no part in this ranking.
#28 of 385 graded solid state drives
- #25 SeagateSeagate FireCuda 530R 4TB 50
- #26 SeagateSeagate FireCuda 530R 4TB 50
- #27 ADATAADATA Legend 960 4TB 50
- #28 Western DigitalWestern Digital WD_Black SN850X 4TB 50
- #29 Western DigitalWestern Digital Black SN850X 4TB 50
- #30 SeagateSeagate FireCuda 530 4TB 50
- #31 Western DigitalWestern Digital SN850P 4TB 50
Value Game
How much of that you get for today’s price.
#16 of 385 currently priced solid state drives
- #13 CorsairCorsair MP600 CORE XT 4TB 85
- #14 TeamGroupTeamGroup Force Vulcan 4TB 84
- #15 Western DigitalWestern Digital SN8100 8TB 84
- #16 Western DigitalWestern Digital WD_Black SN850X 4TB 84
- #17 TeamGroupTeamGroup FORCE G70 PRO Aluminum 4TB 83
- #18 CorsairCorsair MP600 CORE 4TB 82
- #19 Western DigitalWestern Digital Black SN850X 8TB 81
Performance Heavy Creative Work
How much it can do. Price plays no part in this ranking.
#84 of 385 graded solid state drives
- #81 Western DigitalWestern Digital Blue SN5100 1TB 48
- #82 Western DigitalWestern Digital Black SN850X 8TB 47
- #83 Western DigitalWestern Digital Black SN850X 8TB 47
- #84 Western DigitalWestern Digital WD_Black SN850X 4TB 47
- #85 Western DigitalWestern Digital Black SN850X 4TB 47
- #86 Western DigitalWestern Digital SN850P 4TB 47
- #87 SabrentSabrent Rocket Plus 4TB 47
Value Heavy Creative Work
How much of that you get for today’s price.
#47 of 290 currently priced solid state drives
- #44 CorsairCorsair MP700 Elite 1TB 30
- #45 TeamGroupTeamGroup FORCE G70 PRO Aluminum 4TB 30
- #46 Western DigitalWestern Digital Blue SN5100 2TB 29
- #47 Western DigitalWestern Digital WD_Black SN850X 4TB 29
- #48 SeagateSeagate FireCuda 530R 2TB 29
- #49 PatriotPatriot Viper VP4300 Lite 2TB 29
- #50 PatriotPatriot Viper VP4300 Lite 4TB 29
These ladders follow the preset scenario shown above. Your own weights re-score this product, not the whole field.
What it is good for
| Scenario | this productCapability grade · Value at current price | Higher capability | Higher Value with current priorities |
|---|---|---|---|
| Balanced (all-round)Weighted all-round view | GradeNo grade Value68 | Higher capability Crucial T710 1TB 91 +104% capability · -66% price | Higher Value with current priorities Crucial T705 2TB 100 +99% capability · -46% price |
| System DriveScenario capability | GradeS Value28 | Higher capability Higher capability · Higher Value with current priorities Crucial T710 1TB S 100 +104% capability · -66% price | |
| Game & File StorageScenario capability | GradeS Value84 | — | Higher Value with current priorities TeamGroup MP44Q 4TB S 100 +0% capability · -24% price |
| Heavy Creative WorkScenario capability | GradeS Value29 | Higher capability Western Digital SN8100 2TB S 85 +112% capability · -36% price | Higher Value with current priorities Crucial T710 4TB S 98 +108% capability · +8% price |
Balanced has no letter: it is a weighting preset, not a capability rubric. A grade answers “how well does this handle that job?” — price is never part of it. Relative Value puts the current market price back in.
Trade-offs
Works well if
- System Drive is your main prioritygraded S for System Drive on the same rubric as the tier list
- Strong-value threshold: ~$515$515 is where Relative Value reaches 80 with Balanced priorities, in the 2026-09-27 offer frame
Consider other options if
- Current price sits $135 above the strong-value threshold (~$515)cheapest tracked $650 against a $515 calculated threshold with Balanced priorities
- Value for money matters more to you than this exact modelCrucial T705 2TB holds Relative Value 100 against its 68 with Balanced priorities, at $350
Works well if
- System Drive is your main prioritygraded S for System Drive on the same rubric as the tier list
Consider other options if
- You want strong value for System Drive specificallycompeting products deliver so much more for System Drive per dollar that no price this model realistically trades at reaches the strong-value mark for this job
- Value for money matters more to you than this exact modelCrucial T710 1TB holds Relative Value 100 against its 28 for System Drive, at $220
- You are buying for System Drive and want no asterisksthe rubric caps this grade: read speed taken from another capacity of the same drive family — not measured for this exact model
Works well if
- Game is your main prioritygraded S for Game on the same rubric as the tier list
- Today's price already clears the strong-value markcheapest tracked $650 against a $694 threshold for Game
Consider other options if
- Value for money matters more to you than this exact modelTeamGroup MP44Q 4TB holds Relative Value 100 against its 84 for Game, at $493
Works well if
- Heavy Creative Work is your main prioritygraded S for Heavy Creative Work on the same rubric as the tier list
Consider other options if
- You want strong value for Heavy Creative Work specificallycompeting products deliver so much more for Heavy Creative Work per dollar that no price this model realistically trades at reaches the strong-value mark for this job
- You are buying for Heavy Creative Work and want no asterisksthe rubric caps this grade: write speed inferred, not measured for this exact model
Every line states the fact it was derived from, for the scenario selected above. Thresholds are calculated points on our value curve — information about where the maths turns, not instructions about what to pay.
Similar options to the Western Digital WD_Black SN850X 4TB
Chosen for Balanced
Chosen for System Drive
Chosen for Game
Chosen for Heavy Creative Work
Alternatives stay near this product’s price range. Step-up options may exceed the standard budget envelope when the capability gain is meaningful.
Upgrade planner
Judge the change in the active scenario, then make the cash gap explicit.
Using page scenarioWhat are you upgrading from? These are the axes we compare on, and where this product stands in the current market.
Capability differences are expressed as tiers and index points, not as benchmark percentages we did not measure.
Specifications & compatibility
What this product is, and what to check before it goes into your build.
Performance
- Sequential read
- 7300 MB/s
- Sequential write
- 6600 MB/s
- Random read
- 0 IOPS
- Random write
- 0 IOPS
- Controller
- WD Proprietary
Media
- Capacity
- 4 TB
- NAND type
- SanDisk 112-layer TLC
- DRAM cache
- 4GB DDR4
Power / Interface
- Interface
- M.2 PCIe 4.0 x4
- Form factor
- M.2-2280
Physical / Outputs
- Heatsink included
- No
Show all specifications
Endurance & warranty
- Endurance
- 2400 TBW
- Warranty
- 5 years
- Manufacturer part number
- WDS400T2X0E
Hover any value to see where it came from: a manufacturer specification, or a figure The Comparator calculated.
Sources: Comparator offer frame 2026-09-27
What to check in your build
M.2-2280
The slot must take M.2-2280
M.2 PCIe 4.0 x4
PCIe 4.0 M.2 slot for full speed
PCIe 4.0 — runs in older slots at their speed
Fits under an M.2 shroud
Bare drive — it fits under a motherboard M.2 shroud
Meets the PS5 expansion requirements
M.2 2280 NVMe, PCIe 4.0, 7300 MB/s read — meets Sony's published requirements; a heatsink is required
Found an error? Report this specification Email the field, corrected value and an optional source.
Compatibility guidance is practical help, not a score. Missing data is shown as unknown, never invented.
Summary
Western Digital WD_Black SN850X 4TB offers a balanced view across an all-round mix of priorities. It ranks #78 by capability in the current modelled field. Its clearest measured strength is drive capability 7300. Crucial T705 2TB currently clears the same practical bar with stronger Relative Value.
Western Digital WD_Black SN850X 4TB offers S-grade capability for System Drive. It ranks #78 by capability in the current modelled field. Its clearest measured strength is drive capability 7300. Crucial T705 2TB currently clears the same practical bar with stronger Relative Value.
Western Digital WD_Black SN850X 4TB offers S-grade capability for Game. It ranks #28 by capability in the current modelled field. Its clearest measured strength is drive capability 7300. TeamGroup MP44Q 4TB currently clears the same practical bar with stronger Relative Value.
Western Digital WD_Black SN850X 4TB offers S-grade capability for Heavy Creative Work. It ranks #84 by capability in the current modelled field. Its clearest measured strength is drive capability 7300. Crucial T705 2TB currently clears the same practical bar with stronger Relative Value.
FAQ
Why does Relative Value change when I choose another scenario?
Each scenario changes the weights applied to capability, price and the other published factors. The hardware facts stay fixed, but the value question changes, so its score and rank can change too.
Why can Amazon appear without a tracked price?
Amazon is shown as a discovery link when we do not have a permitted verified price snapshot. It is excluded from price comparisons, rankings and Relative Value until a compliant tracked price exists.
Useful links & sources
offer frame 2026-09-27 · formula ssd-value-v1.5 · facts facts-2026-09-27 · Relative Value is an estimate from our current dataset, the selected weights and dated market prices — not an official product rating and not a price forecast. Target prices are calculation thresholds, not predictions. Methodology We are not a shop. Affiliate links may earn us a commission; they never change the calculations or the ranking.