Western Digital SN5000 4TB Review — QLC Capacity Play With Gen4 Pace (2026)
Quick answer
Buy the Western Digital SN5000 4TB as a bulk-storage Gen4 drive: 4 TB of single-sided M.2 with 5,500 MB/s reads, 900K random-write IOPS and five years of coverage is a strong package for game libraries, media volumes and PS5-style expansion where read speed dominates.
Read: 5500 MB/s Write: 5000 MB/s Endurance: 1200 TBW Warranty: 5 years Interface: M.2 4.0 x 4
The Western Digital SN5000 4TB trades the line's TLC for QLC, gains the family's fastest 5,500 MB/s rating and hits 4 TB at a mainstream price positioning.
Controller & Memory
The Western Digital SN5000 4TB is the odd member of its own family. Where the 500 GB to 2 TB models run Kioxia BiCS5 112-layer TLC on a DRAM-less in-house controller, the 4 TB switches to BiCS6 162-layer QLC and, per Blocks & Files, a different controller as well — WD built this capacity as a dedicated high-density part rather than scaling the small ones up. The changes flatter the spec sheet: WD rates this model at 5,500 MB/s sequential reads and 5,000 MB/s writes, the fastest figures in the SN5000 range, with 690K random-read and 900K random-write IOPS on a single-sided M.2 2280 board.
The endurance table tells the trade-off. This model is rated at 1,200 TBW under the 5-year limited warranty — double the 2 TB's 900 TBW, but a lower per-terabyte ratio than the TLC capacities carry, the standard QLC concession. Tom's Hardware's 4TB review framed 5,500 MB/s as the optimal read speed for PS5-class use, and TweakTown's review emphasised the low power draw and high capacity; The SSD Review's take was literally titled 'TLC or QLC Memory You Pick'. All three note the QLC catch: once the pseudo-SLC cache under nCache 4.0 exhausts during very large sustained writes, throughput settles far below the rated figure — a few hundred MB/s rather than 5,000.
The buyer for this capacity wants bulk, not burst: a 4 TB game library, a media volume, or a PS5 storage expansion where reads matter far more than sustained writes. Against the Crucial P3 Plus 4 TB, another QLC drive, the SN5000 holds the ratings advantage and the more consistent family reputation; Samsung's 990 EVO Plus and Kingston's NV3 cover the TLC-first and price-first angles respectively. No heatsink is included, so plan on one for console or hot small-form-factor builds.
Storage Comparisons:
SN5000 Performance & Benchmarks
WD rates the 4TB SN5000 at 5,500 MB/s sequential reads, 5,000 MB/s writes, 690K random-read and 900K random-write IOPS — the strongest ratings in the family, and 5,500 MB/s happens to match Sony's recommended read speed for PS5 expansion. Tom's Hardware's 4TB review called that read speed optimal for console-class use and delivered a positive verdict on the mature platform; TweakTown highlighted the capacity-per-watt angle. For reads the drive behaves like any healthy Gen4 drive: 5,500 MB/s loads games, levels and DirectStorage assets with headroom to spare.
Western Digital SN5000 4 TB 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 SN5000 4 TB (this drive): 5,500 MB/s read, 5,000 MB/s write
Writes are where the QLC shows. The nCache 4.0 pseudo-SLC cache absorbs installs and everyday copies at rated speed, but sustained transfers that outlast the cache drop to a fraction of the 5,000 MB/s figure — independent reviewers consistently measured post-cache throughput in the few-hundred-MB/s band, with ServeTheHome's early 4 TB testing lining up with reader-reported figures around the 500-600 MB/s mark. For a game library that pattern is irrelevant — installs are cache-friendly bursts — but for constant video ingest or scratch duty, a TLC or DRAM-equipped drive is the better tool. Random performance is strong for a DRAM-less design, and thermals stayed manageable in reviews, though a heatsink remains worth adding.
Western Digital SN5000 vs Competitors
See how the SN5000 stacks up against other M.2 4.0 x 4 drives in our database:
Compare with rival drives:
Endurance, TBW & Warranty
WD backs the SN5000 4TB with a 5-year limited warranty rated to 1,200 TBW of writes, whichever arrives first. That is the largest endurance budget in the family in absolute terms — the 2 TB is rated at 900 TBW and the 1 TB at 600 — but the QLC NAND means the per-terabyte ratio actually drops at this capacity, and WD's own scaling confirms the 4 TB is not simply the 1 TB multiplied. At 20 GB of writes per day, 1,200 TBW stretches past 160 years, so the warranty term is the practical limit. Support runs through WD's standard channels with WD Dashboard handling firmware and health reporting. The SSD Review characterised the endurance as adequate for the drive's bulk-storage mission.
Western Digital SN5000 4 TB Specifications
| Category | Value |
|---|---|
| Capacity [?] | 4 TB |
| Interface [?] | M.2 4.0 x 4 |
| Controller [?] | WD in-house |
| Memory type [?] | BiCS 6 3D QLC |
| DRAM [?] | No |
| Read speed (MB/s) [?] | 5500 |
| Write speed (MB/s) [?] | 5000 |
| Read IOPS [?] | 690000 |
| Write IOPS [?] | 900000 |
| Endurance (TBW) [?] | 1200 |
| MTBF (million hours) [?] | n/a |
| Warranty (years) [?] | 5 |
Verdict: Is the SN5000 Worth It in 2026?
Buy the Western Digital SN5000 4TB as a bulk-storage Gen4 drive: 4 TB of single-sided M.2 with 5,500 MB/s reads, 900K random-write IOPS and five years of coverage is a strong package for game libraries, media volumes and PS5-style expansion where read speed dominates. Skip it for sustained heavy writing — the QLC NAND concedes post-cache throughput that TLC capacities keep, and a DRAM-equipped alternative holds up better there. The Crucial P3 Plus 4 TB is the like-for-like QLC rival, Samsung's 990 EVO Plus the speed-first option, and the SN5000 2 TB the pick if 2 TB is genuinely enough capacity. For a QLC capacity play executed this carefully, the SN5000 4TB earns its place in the WD Blue range.
+ Pros
- 5,500 MB/s reads, the fastest in the SN5000 family
- 900K random-write IOPS rating
- 1,200 TBW endurance with 5-year warranty
- Single-sided M.2 2280 fits PS5 and thin laptops
- Read rating matches Sony's 5,500 MB/s PS5 recommendation
- Cons
- QLC NAND where 500 GB-2 TB models use TLC
- Post-cache sustained writes drop to a few hundred MB/s
- Lower TBW-per-TB ratio than the TLC capacities
- No heatsink included
Buy this or similar SSD Storage:
Video Review
MOST IMPRESSIVE SSD yet - Cheaper & FASTER! | WD Blue SN5000 review
