Western Digital SN8100 4 TB: WD's Highest-Shipping Gen5 Capacity (2026)
The Western Digital SN8100 4 TB is the highest-shipping capacity of WD's PCIe 5.0 flagship, pairing a 2,400 TBW endurance cushion with the same 14,900 MB/s peak every reviewer called the fastest consumer SSD they tested.
Controller & Memory
The Western Digital SN8100 4 TB is the highest-capacity shipping member of WD's first PCIe 5.0 flagship family, built on the same Silicon Motion SM2508 platform every major outlet reviewed at the 2 TB launch. Under the label sits the SM2508 eight-channel controller built on TSMC's 6 nm process, paired with Kioxia BiCS8 218-layer 3D TLC NAND at 3,600 MT/s, a discrete Micron DDR4-3200 DRAM cache, SanDisk's nCache 4.0 pseudo-SLC caching layer, and Silicon Motion's NANDXtend ECC. WD rates the 4 TB at 14,900 MB/s sequential reads, 14,000 MB/s writes, and up to 2.3 million random read IOPS and 2.4 million random write IOPS over a PCIe 5.0 x4 link, identical to the rest of the family since peak speeds do not scale with capacity; only endurance does.
Where the 4 TB stands apart is capacity and endurance. It carries a 2,400 TBW rating, double the 2 TB's 1,200 TBW and quadruple the 1 TB's 600 TBW, scaling at the family's 600 TBW-per-terabyte rate on Kioxia BiCS8 TLC. That makes it the highest-endurance shipping SN8100, since the 8 TB SKU, rated 4,800 TBW, is announced but not yet available at retail. The larger NAND footprint also gives the 4 TB a proportionally bigger pseudo-SLC cache than the 2 TB, which on the reviewed 2 TB held 8 GB/s burst writes through roughly 623 GB before settling to around 4 GB/s direct to TLC; the 4 TB holds that burst headroom through a larger write window, which matters for video ingest and large project transfers. WD rates active power at 6.5 W under reads and 7.0 W under writes, shared with the 2 TB.
The honest caveat is that no major outlet has reviewed a dedicated 4 TB unit. Every independent review, from TechPowerUp, Tom's Hardware, StorageReview, TweakTown, and PC Mag, tested the 2 TB launch SKU, so the 4 TB's performance picture is scaled from the shared SM2508 platform rather than measured on this exact capacity. Compatibility is the standard Gen5 story: the SN8100 4 TB earns its keep only in a recent AMD 600-series or Intel 700-series desktop with a PCIe 5.0 M.2 slot, runs at half speed in a PlayStation 5, and is largely wasted in a laptop. The base drive ships bare with no heatsink in the box, and sustained Gen5 writes still push the SM2508 hard enough that motherboard heatsink coverage is close to mandatory, though WD also sells a factory heatsink variant. The closest rivals are the Crucial T705 and Seagate FireCuda 540 on the Phison E26 tier, the Samsung 9100 Pro at the top of the Gen5 stack, and the Kingston Fury Renegade G5 on the same SM2508 silicon.
Storage Comparisons:
SN8100 Performance & Benchmarks
Every independent review of the SN8100 family tested the 2 TB launch capacity, so the 4 TB's real-world characterisation is built on the shared SM2508 platform rather than a dedicated 4 TB review unit. Tom's Hardware titled its 2 TB verdict "the fastest overall consumer SSD ever made," TechPowerUp called it "the fastest and most energy-efficient SSD we have ever tested," TweakTown framed the random-access latency as "approaching Optane," and StorageReview found it "outperforms its competition in most of our benchmarking." WD rates the 4 TB at 14,900 MB/s sequential reads, 14,000 MB/s writes, 2.3 million random read IOPS, and 2.4 million random write IOPS over PCIe 5.0 x4, identical to every other capacity in the family and essentially saturating the Gen5 ceiling.
WESTERN DIGITAL SN8100 4 TB vs M.2 5.0 peers
Switch between sequential throughput and random IOPS to see how this drive stacks up against other M.2 5.0 SSDs in our database. The highlighted bar is the drive on this page — click any other bar to open that drive.
- WESTERN DIGITAL SN8100 4 TB (this drive): 14,900 MB/s read, 14,000 MB/s write
- Corsair MP700 Pro XT 1 TB: 14,900 MB/s read, 14,200 MB/s write
- Corsair MP700 Pro XT 2 TB: 14,900 MB/s read, 14,500 MB/s write
- Corsair MP700 Pro XT 4 TB: 14,900 MB/s read, 14,400 MB/s write
- Crucial T710 1 TB: 14,900 MB/s read, 13,800 MB/s write
The 4 TB's genuine edge over its smaller siblings is sustained-write headroom. The reviewed 2 TB held 8 GB/s burst writes until roughly 623 GB filled, about 90 percent of its capacity in SLC mode, then settled to around 4 GB/s direct to TLC with a 2.5 GB/s full-fill average. The 4 TB's larger NAND footprint gives it a proportionally bigger pseudo-SLC cache, so it holds that burst ceiling through a larger window before the direct-to-TLC drop, which matters for anyone moving 100 GB-plus video ingests or full game-library migrations. The leap over PCIe 4.0 is real on sequential bandwidth but modest for game load times, which are bounded by the CPU and asset decompression; a Samsung 990 Pro or WD Black SN850X feels near-identical in most current titles. The SM2508's efficiency edge over Phison E26 holds on the 4 TB as well: at 6.5 W read and 7.0 W write it draws less power, throttles less, and holds rated speed longer than the E26 competition.
WESTERN DIGITAL SN8100 vs Competitors
See how the SN8100 stacks up against other M.2 5.0 drives in our database:
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Endurance, TBW & Warranty
WD covers the SN8100 4 TB with a five-year limited warranty, ending early only if the 2,400 TBW endurance rating is exceeded, whichever comes first. That 2,400 TBW figure sits at the top of the shipping family, which scales at 600 TBW per terabyte of Kioxia BiCS8 TLC: 600 TBW on the 1 TB, 1,200 TBW on the 2 TB, 2,400 TBW on the 4 TB, and 4,800 TBW on the announced 8 TB. At a typical consumer workload of around 20 GB of writes per day, the 4 TB would need more than 320 years to exhaust the NAND, so the flash outlasts the warranty term by a wide margin; even a heavier 100 GB-per-day routine still clears six decades. WD rates the drive at up to two million hours MTBF, though StorageReview cites an MTTF of 1.75 million hours for the SN8100; treat either figure as a population-reliability statistic describing expected failures across a large fleet, not a lifespan guarantee for any single unit.
WESTERN DIGITAL SN8100 4 TB Specifications
| Category | Value |
|---|---|
| Capacity [?] | 4 TB |
| Interface [?] | M.2 5.0 |
| Controller [?] | Silicon Mortion SM2508 |
| Memory type [?] | Kioxia 3D TLC |
| DRAM [?] | Yes |
| Read speed (MB/s) [?] | 14900 |
| Write speed (MB/s) [?] | 14000 |
| Read IOPS [?] | 2300000 |
| Write IOPS [?] | 2400000 |
| Endurance (TBW) [?] | 2400 |
| MTBF (million hours) [?] | 2000000 |
| Warranty (years) [?] | 5 |
Verdict: Is the SN8100 Worth It in 2026?
Buy the Western Digital SN8100 4 TB for a PCIe 5.0-capable desktop when the workload is capacity- and endurance-bound, since the 2,400 TBW cushion and larger pseudo-SLC cache give the SM2508 platform more sustained-write headroom than the 2 TB. Skip it on a PCIe 4.0-only board, where it runs at half speed and a Samsung 990 Pro 4 TB matches its responsiveness at a lower cost, and on a PlayStation 5, whose PCIe 4.0 slot cannot use the Gen5 bandwidth. The honest caveat is that no major outlet has reviewed a dedicated 4 TB unit, so the performance picture is scaled from the 2 TB launch SKU. The closest alternatives are the Kingston Fury Renegade G5 4 TB on the same SM2508 silicon, or the Samsung 9100 Pro 4 TB at the top of the Gen5 stack. The verdict: the highest-endurance shipping SN8100, built for builders who need the room.
+ Pros
- 14,900 MB/s sequential reads over PCIe 5.0
- Silicon Motion SM2508 6 nm Gen5 controller
- Kioxia BiCS8 218-layer TLC at 3,600 MT/s
- 2,400 TBW endurance, highest shipping capacity
- Larger pseudo-SLC cache than the 2 TB sibling
- 6.5 W read draw, lower than Phison E26 rivals
- Five-year warranty with NANDXtend ECC
- Cons
- No dedicated 4 TB review unit exists
- No heatsink included on the bare SKU
- PCIe 5.0 wasted on PS5 and Gen4 boards
- Modest real-world game gains over PCIe 4.0
- 8 TB capacity announced but not shipping
Buy this or similar SSD Storage:
Video Review
Destroying The Competition - WD Black SN8100 SSD Review
