WD Black SN850X Review: Still the Gamer's PCIe 4.0 Pick

What the SN850X is

The WD Black SN850X is WD's flagship gaming SSD for the PCIe 4.0 generation, launched in August 2022. Rated sequential speeds hit 7,300 MB/s read on every capacity; writes are 6,300 MB/s at 1TB and 6,600 MB/s from 2TB up, with 1.2M/1.1M 4KB random read/write IOPS on the 2TB model. It pairs WD's in-house controller with 112-layer Kioxia BiCS5 TLC flash and a full DRAM cache that scales with capacity (2GB on the 2TB). Capacities ran 1TB to 4TB at launch, with an 8TB model added later on newer BiCS6 NAND; each size comes bare or with a factory heatsink, and the heatsink SKU is the PS5-certified one. Game Mode 2.0 — Predictive Loading, Overhead Balancing, Adaptive Thermal Management — is enabled through the downloadable WD Dashboard, which is Windows-only, and the drive supports Microsoft DirectStorage. The warranty is five years; endurance is rated at 600 TBW for the 1TB and 1,200 TBW for the 2TB, with a 1.75-million-hour MTBF. This review centers on the 2TB bare model (WDS200T2X0E), the mainstream pick, with the heatsink version (WDS200T2XHE) noted where relevant. Everything below comes from manufacturer specs, published reviews, and owner reports — JudgeAny runs no lab and measured nothing itself.

Sequential and trace performance

Tom's Hardware's 1TB review (August 2022, re-tested that October) gave the drive 4 out of 5 stars and an Editor's Choice badge, calling it 'one of the more consistent and well-balanced Gen 4 SSDs' and keeping it on its Best SSDs for PS5 list. In its testing the SN850X placed second in 3DMark's Storage Benchmark behind only the SK hynix Platinum P41, and ran right behind the P41 in PCMark 10 with Game Mode off. Tech Advisor's 2TB test measured 7,377 MB/s reads and 6,673 MB/s writes in CrystalDiskMark's default settings — a 5% read and 28% write gain over the older SN850 — and called the X 'an unequivocal improvement over the SN850'. KitGuru's deep test of the 2TB heatsink model logged the fastest single-queue-depth 4K random write it had seen from a consumer drive (213,859 IOPS), while noting its measured figures at high queue depths land well short of the official 1.1M IOPS claim.

Game loads: where it wins — and the Game Mode 2.0 caveat

In a same-board head-to-head against the Samsung 990 Pro, Custom PC found the SN850X winning the single-queue-depth 4K tests and loading games faster: Battlefield V at 1,154 vs 1,035 MB/s, Call of Duty: Black Ops at 965 vs 739 MB/s, with lower access times. That conflicts with Tom's Hardware's own 990 Pro review, which called Samsung's low-queue-depth reads 'the best we've yet tested'. Different rigs, different runs: both drives sit at the PCIe 4.0 ceiling and trade wins, with the published game-load numbers going WD's way.

The marketing claim that doesn't survive contact with testing is Game Mode 2.0. Tom's Hardware found it made no difference in ATTO and only trimmed latency slightly in CrystalDiskMark's 4K tests, calling it 'a bit gimmicky'; Tech Advisor likewise found minimal impact in most benchmarks. The drive earns its gaming reputation in game-load traces, not from the toggle — and the WD Dashboard that switches it on is Windows-only.

One more wrinkle for the 'flagship' label: WD's own newer SN7100 outscored the SN850X in PCMark 10 (4,561 vs 3,846 in a published comparison drawing on Tom's numbers, about 19% higher), while the SN850X answered in 3DMark's gaming trace with a near-10% win. So the SN850X is no longer WD's best all-rounder — its lead over the field is really only in gaming and PS5 duty.

Thermals, sustained writes, and software

The SN850X runs hot. Tom's Hardware measured the bare drive at 78-85°C under load — a heatsink is effectively required to hold full speed, and WD sells exactly that version. PCGamesN tested the RGB-lit heatsink model and saw 69°C as a worst-case extended stress result; NASCompares, running the drive under a cheap aftermarket heatsink, averaged around 48°C between benchmark runs while noting the drive 'certainly ran quite hot'. What the thermals buy is consistency: Tom's Hardware puts the 2TB model's pSLC cache at roughly 600GB, so long writes hold speed instead of falling off. One number worth noting: PC Gamer found peak sequential writes trailing the rated figures (5,940 MB/s on its 1TB sample), so treat headline speeds as ceilings, not floors.

On the practical side, installation is a standard M.2 2280 drop-in, and the heatsink SKU fits the PS5's expansion slot. The WD Dashboard is Windows-only, there is no hardware encryption (Club386 flags it as no big miss on a consumer drive), and Club386 notes the 2TB's 1,200 TBW works out to about 0.33 drive writes per day — fine for gaming, though rivals like the FireCuda 530 rate over twice that.

Owner impressions match the reviews. Amazon's SN850X listings carry a 4.8/5 rating across tens of thousands of ratings (Slickdeals and Notebookcheck both cite it), Best Buy shows 4.9/5 from 979 reviews with 99% recommending, and the recurring praise is for speed and easy drop-in installs — especially PS5 upgrades — while the recurring complaints mirror the professional verdict: it runs hot, the Dashboard is Windows-only, and the list price stings until a sale.

Who should buy it

Buy the SN850X for a gaming PC or a PS5 storage upgrade — the heatsink SKU for the console, the bare drive under a motherboard heatsink for desktops. It is the drive Tom's Hardware still keeps on its PS5 list, and the published game-load numbers beat its closest rival. Skip it if your workload is sustained mixed-write productivity, where the 990 Pro and even WD's own SN7100 measured faster in PCMark 10; if you need hardware encryption; or if you're building on PCIe 5.0, where newer (hotter, pricier) drives exist. Don't confuse it with the older SN850 — the X is the real step up, especially in writes. Check the live Amazon price.