The WD Black SN850X announced by Western Digital in May is now on store shelves. The PCIe 4.0 SSD boasts read speeds of up to 7300 MBps and aims to contend for a place among the best of his SSDs.
SN850X comes in a standard M.2 2280 form factor. Therefore, the SSD fits both PC and Sony’s PlayStation 5 console. Western Digital sells the drive with an optional heatsink with RGB lighting to keep the peak performance, but PlayStation 5 owners find the bulky heatsink too much to fit inside the console. You should choose the standard model as it takes up a lot of space.
Western Digital did not specify the type of controller or 3D NAND used to manufacture the SN850X. However, we expect the high-speed drives to use one of the in-house PCIe 4.0 SSD controllers. The WD Black SN850 uses the WD Black G2 controller, so Western Digital will likely use the same controller in the X variant. Judging by the SN850X’s endurance rating, PCIe 4.0 drives will likely rock TLC (Triple Level Cell) NAND. Unfortunately, it is not possible to identify which one. For reference, his original WD Black SN850, launched last year, used 4th generation BiCS 96-layer NAND. Since then, Western Digital and Kioxia (formerly Toshiba) have developed 112-layer and 162-layer NAND chips, allowing the SN850X to use one of his two.
Western Digital’s SN850X comes in 1TB, 2TB and 4TB capacities, but the models with heatsinks are only 1TB and 2TB. Regardless of capacity, the SN850X delivers sequential read speeds of up to 7,300 MBps. Sequential write speeds, on the other hand, vary slightly with capacity. Only 2TB and 4TB can hit 6,600 MBps, but 1TB drives top out at 6,300 MBps, which isn’t too shabby.
WD Black SN850X Specifications
| Product No | capacity | Sequential read (MBps) | Sequential Writes (MBps) | Random read (IOPS) | Random writes (IOPS) | Endurance (TBW) | heatsink | price |
|---|---|---|---|---|---|---|---|---|
| WDS400T2X0E | 4TB | 7,300 | 6,600 | 1.2 million | 1.1 million | 2,400 | No | $699.99 |
| WDS200T2XHE | 2TB | 7,300 | 6,600 | 1.2 million | 1.1 million | 1,200 | yes | $309.99 |
| WDS200T2X0E | 2TB | 7,300 | 6,600 | 1.2 million | 1.1 million | 1,200 | No | $289.99 |
| WDS100T2XHE | 1TB | 7,300 | 6,300 | 800,000 | 1.1 million | 600 | yes | $179.99 |
| WDS100T2X0E | 1TB | 7,300 | 6,300 | 800,000 | 1.1 million | 600 | No | $159.99 |
The SN850X 2TB and 4TB SSDs offer random read and write performance of up to 1,200,000 IOPS and 1,100,000 IOPS respectively. The 1TB version checks in at 800,000 IOPS read and 1,100,000 IOPS write.
Comparing the SN850X to its predecessor SN850 shows 4% higher sequential reads and 25% higher sequential writes. Random read and write speeds improved by 20% and 53%, respectively.
The SN850X offers a significant performance boost, but unfortunately the SSD isn’t as durable as its predecessor. Western Digital rates the SN850X 1 TB, 2 TB, and 4 TB at 600 TBW, 1,200 TBW, and 2,400 TBW respectively. This is the exact endurance of the SN850 1TB and SN850 2TB. For the SN850, Western Digital didn’t offer his 4TB model. The SN850X is covered by the vendor’s limited 5-year warranty.
Western Digital has a 1TB drive $159.99 (opens in new tab)2TB drives $289.99 (opens in new tab)and 4 TB drives $699.99 (opens in new tab) at its online store. His 1TB and 2TB models with optional heatsinks carry a $20 surcharge. If you purchased your SN850X from another retailer, there will be some price differences. For example, SN850X 4TB ( momomo_us (opens in new tab)) retailers $820.37 (opens in new tab) on Amazon.
