WD Black SN770 250GB PCIe 4.0 NVMe SSD Review (2026)

Name: Western Digital Black SN770 250 GB
Brand: Western Digital
SKU: western-digital-black-sn770-250-gb
Rating: 4.5 (94 reviews)

Posted on May 17, 2026 by Raymond Chen

The WD Black SN770 250GB is the entry rung of an otherwise capable PCIe 4.0 lineup, and at this capacity its DRAM-less design and halved write rating tell you exactly who it is meant for.

WD Black SN770 250GB PCIe 4.0 NVMe SSD Review

Controller & Memory

Western Digital builds the SN770 around an in-house SanDisk-designed four-channel NVMe controller paired with BiCS5 112-layer Kioxia 3D TLC NAND. There is no onboard DRAM cache; the drive leans on the NVMe Host Memory Buffer (HMB) feature to borrow a small slice of system RAM for its mapping table. The PCB is single-sided M.2 2280, which is helpful for ultrabooks, mini PCs, and PS5-style enclosures where bottom-side components can foul the slot. No heatsink ships in the box, but the SN770 is a moderate-power drive and rarely throttles in typical desktop use.

The SN770 is sold in 250 GB, 500 GB, 1 TB, and 2 TB capacities, and this is the smallest, lowest-binned variant in the family. WD rates the 250 GB sheet at 4,000 MB/s sequential reads and only 2,000 MB/s sequential writes, with 240,000 random read IOPS and 470,000 random write IOPS. Compared to the 1 TB SKU's 5,150/4,900 MB/s rating, the 250 GB sheet is dramatically slower on writes because fewer NAND dies can be interleaved in parallel. Buyers shopping this size are almost always treating it as a small boot drive, a secondary game volume, or a budget upgrade for an older PCIe 3.0 laptop.

In that role, its direct rivals are the WD Blue SN580 250 GB, the Crucial P3 Plus, the Kingston NV2, and Samsung's older 980 (non-Pro). The SN770 still has the edge in random performance and warranty length among the DRAM-less Gen4 cohort. Anyone considering this drive for a PS5 expansion should look at the 1 TB or 2 TB SN770 instead — the 250 GB is well below Sony's 5,500 MB/s read recommendation.

Storage Comparisons:

Best PCIe 4.0 SSD Drive Best Deal of 1 TB SSDs NVME Top 2 TB SSDs

Black SN770 Performance & Benchmarks

WD rates the 250 GB SN770 at up to 4,000 MB/s sequential reads and 2,000 MB/s sequential writes, with 240,000 random read IOPS and 470,000 random write IOPS. Those numbers comfortably beat any SATA SSD and roughly match a mid-tier PCIe 3.0 drive on reads, but the 2,000 MB/s write rating is the headline trade-off at this capacity — it is less than half of what the 1 TB SN770 delivers and well under what flagship Gen4 drives manage. For boot, OS, and game-launch workloads this is largely invisible; for large file copies it is the moment the spec sheet starts to bite.

Performance comparison

Western Digital Black SN770 250 GB vs M.2 4.0 x 4 peers

Switch between sequential throughput and random IOPS to see how this drive stacks up against other M.2 4.0 x 4 SSDs in our database. The highlighted bar is the drive on this page — click any other bar to open that drive.

Patriot Viper PV593 1 TB: 14,500 MB/s read, 14,000 MB/s write
Patriot Viper PV593 2 TB: 14,500 MB/s read, 14,000 MB/s write
Patriot Viper PV593 4 TB: 14,500 MB/s read, 14,000 MB/s write
Patriot Viper PV573 2 TB: 14,000 MB/s read, 12,000 MB/s write
Western Digital Black SN770 250 GB (this drive): 4,000 MB/s read, 2,000 MB/s write

Like most TLC NVMe drives, the SN770 uses a dynamic SLC cache to absorb burst writes. On a 250 GB drive that cache is small, and independent reviewers consistently find that sustained writes drop sharply once the cache fills — into the few-hundred MB/s range on extended transfers. Combined with the DRAM-less HMB design, mixed and queued random workloads also lag behind DRAM-equipped drives such as the WD Black SN850X or Samsung 990 Pro. For everyday gaming, productivity, and even DirectStorage workloads the SN770 250 GB feels snappy, but creators moving multi-gigabyte project files or building a Steam library on this drive will run into the cache wall regularly.

Western Digital Black SN770 vs Competitors

See how the Black SN770 stacks up against other M.2 4.0 x 4 drives in our database:

Compare with rival drives:

MSI Spatium M450 250 GB Micron 2450 256 GB Kingston NV2 256 GB

Endurance, TBW & Warranty

Western Digital backs the SN770 with a 5-year limited warranty, and on the 250 GB capacity the endurance allowance is 200 TBW — about a fifth of what the 1 TB model carries. That works out to roughly 110 GB of writes every single day for five years before the rating is exhausted, which is more than a typical home user will write to a small system drive in a decade. The warranty ends at whichever boundary is reached first: five calendar years, or 200 TBW of host writes.

WD lists an MTBF of 1,750,000 hours for the SN770 family. As always, MTBF is a fleet-level statistical projection, not a guarantee that an individual drive will live a specific number of hours. Western Digital handles warranty claims directly through its support portal, which is generally faster than going through the retailer once the original return window has closed. Buyers planning sustained heavy writes — large video archives, constant Steam reinstalls, or scratch-disk use for editing — should step up to a higher capacity where the TBW headroom is meaningful.

Western Digital Black SN770 250 GB Specifications

Category	Value
Capacity [?]	250 GB
Interface [?]	M.2 4.0 x 4
Controller [?]	SanDisk
Memory type [?]	Kioxia 112-L TLC
DRAM [?]	No (HMB)
Read speed (MB/s) [?]	4000
Write speed (MB/s) [?]	2000
Read IOPS [?]	240000
Write IOPS [?]	470000
Endurance (TBW) [?]	200
MTBF (million hours) [?]	1.75
Warranty (years) [?]	5

Verdict: Is the Black SN770 Worth It in 2026?

The WD Black SN770 250GB is a sensible pick for shoppers who only need a small, fast boot drive in a Gen4 system and want the long warranty and clean WD ecosystem. It is the wrong drive for PS5 expansion, content creation, or any role that demands sustained write speed, where the 2,000 MB/s write rating and 200 TBW allowance both become liabilities. Anyone willing to spend a little more should jump straight to the SN770 1 TB, the WD Blue SN580 1 TB, or a Crucial P3 Plus at a similar capacity — all three deliver dramatically better write performance and far higher endurance for not much more money. As a 250 GB Gen4 boot drive it is fine; as an everyday workhorse it is undersized.

+ Pros

5-year warranty on a budget Gen4 drive
DRAM-less HMB design keeps power draw low
Single-sided M.2 2280 fits laptops and PS5 carriers
In-house SanDisk controller with BiCS5 TLC NAND
PCIe 4.0 reads up to 4,000 MB/s

- Cons

250 GB sheet limited to 2,000 MB/s writes
Only 200 TBW endurance at this capacity
Small SLC cache fills quickly on large copies
No DRAM hurts mixed random performance
Below Sony PS5 5,500 MB/s read recommendation

4.5 / 5 · 94 votes

Buy this or similar SSD Storage:

Samsung 980 Pro 2 TB

-57% $165
List Price: $379.99

Buy on Amazon

INLAND Performance Plus 1 TB

$79.99

Buy on Amazon

Silicon Power 512GB NVMe SSD

$42.97

Buy on Amazon

Video Review

WD Black SN770 SSD Review – Mid Range Gaming Greatness?

Frequently Asked Questions

The WD Black SN770 250GB is acceptable for a small game library but not ideal as a primary gaming drive. The 4,000 MB/s read rating loads games quickly compared to SATA, and DirectStorage-capable titles will benefit from the Gen4 link. The catch is capacity: modern AAA titles often exceed 100 GB each, so 250 GB realistically holds your OS plus two or three games at most. Random read performance is strong for the price tier, but the 2,000 MB/s write rating means game installs and patch downloads finish noticeably slower than on the 1 TB SN770.

The SN770 250GB technically fits the PS5 M.2 slot — it is a PCIe 4.0 NVMe drive in a single-sided 2280 form factor — but Sony recommends a sustained read speed of at least 5,500 MB/s. The 250 GB SN770 is only rated for 4,000 MB/s reads, well below that bar. The console will accept the drive and games will run, but you may see longer load times on titles that aggressively stream assets. For PS5 expansion, the 1 TB or 2 TB SN770 (or a different model entirely) is a much better fit.

No, the SN770 is a DRAM-less drive. Instead of mounting a dedicated DRAM chip, it uses the NVMe Host Memory Buffer (HMB) feature to borrow a small slice of system RAM (typically 32–64 MB) to hold its logical-to-physical mapping table. HMB works well for typical desktop workloads and helps WD hit a lower price point, but it does not match the consistency of a true DRAM cache under heavy random or mixed workloads. DRAM-equipped alternatives like the WD Black SN850X or Samsung 990 Pro hold up better when queue depths climb.

The 250 GB SN770 is rated for 200 TBW (terabytes written) over its 5-year warranty period. That ceiling is whichever comes first — five years on the calendar, or 200 TBW of host writes. In practical terms 200 TBW is around 110 GB of writes per day for five straight years, which is far above what any normal home user produces. Light users will not approach this limit. The number scales with capacity: 500 GB is rated for 300 TBW, 1 TB for 600 TBW, and 2 TB for 1,200 TBW.

For most desktop and laptop installs, the SN770 250GB does not need a heatsink. Its power draw and operating temperatures are modest because the DRAM-less controller runs cool and the 250 GB capacity has few NAND dies to drive. Sustained heavy writes can still push temperatures up, especially in a poorly ventilated motherboard M.2 slot tucked under a GPU, so a thin third-party heatsink is a sensible cheap upgrade. A motherboard-supplied M.2 heatsink is more than enough. PS5 use is the one case where a low-profile heatsink is mandatory per Sony.

Yes, significantly. The 250 GB SN770 is rated at 4,000 MB/s sequential reads and 2,000 MB/s sequential writes, while the 1 TB version is rated at 5,150 MB/s reads and 4,900 MB/s writes — roughly 2.5x the write throughput. Random IOPS also climb on the larger capacity, from 240,000/470,000 on the 250 GB to 740,000/800,000 on the 1 TB. The reason is parallelism: bigger capacities have more NAND packages running side by side. If sequential write performance matters to your workload, skip straight to the 1 TB or 2 TB SN770.

Both the SN770 and Kingston NV2 are DRAM-less PCIe 4.0 NVMe drives aimed at the budget tier, and they share a similar buyer profile: shoppers who want Gen4 bandwidth without paying for DRAM or flagship controllers. The SN770 generally has the edge in random IOPS, warranty length (5 years vs Kingston NV2 limited terms), and consistency thanks to its dedicated WD/SanDisk controller. The NV2 is a moving target because Kingston changes its controller and NAND silently between batches. If predictability matters, the SN770 250GB is the safer pick.