WD_BLACK SN850X 2TB NVMe SSD without heatsink: specs and who it suits

The WD_BLACK SN850X is a 2TB internal gaming SSD that plugs into an M.2 slot and uses the NVMe protocol over PCIe 4.0 x4. This version comes without a heatsink, so it is intended for systems that already provide cooling for the M.2 slot, such as many motherboards with built-in heatsinks. The listing offers few details beyond headline features, so this page explains what those mean.

What PCIe 4.0 x4 NVMe means

NVMe is the protocol modern SSDs use to talk to the processor over PCI Express lanes, and it is much faster than the older SATA interface. The "x4" means the drive uses four lanes, and "PCIe 4.0" is the generation, which typically offers about twice the bandwidth per lane of PCIe 3.0. The drive needs an M.2 slot that supports NVMe; it will work in a PCIe 3.0 slot, but the top speed would then be limited by that slot.

Read speeds of up to 7,300 MB/s

The listing quotes sequential reads of up to 7,300 MB/s, which is close to what a PCIe 4.0 x4 link can carry. Sequential speed describes how fast large files, such as game installations, are read in one go. In everyday use, actual load times also depend on the game, the processor and the storage software, so a faster drive does not shorten every wait by the same amount. The listing gives no write speeds, so check the maker's datasheet if sustained writes matter to you.

Game Mode 2.0

The listing highlights Game Mode 2.0, described as optimising performance for gaming under Windows. It is a software feature associated with the drive's companion tools, and what it does in detail is set out by the manufacturer. If you do not use Windows, check which features are available for your system.

Why "without heatsink" matters

Fast NVMe drives produce heat under sustained load and may slow themselves down if they get too hot. A heatsink spreads that heat. This version leaves it out, which the listing says allows integration with existing cooling systems. Many recent motherboards ship with M.2 heatsinks or covers, and laptops and consoles often have their own thermal arrangements. If your computer has no cooling for the slot, a separate heatsink is something to consider. Check that any heatsink fits in the available height.

2TB of capacity

Two terabytes is enough for a large library of modern games, some of which each take well over 100GB. As with any drive, the operating system reports slightly less than the labelled capacity because of how manufacturers count and because some space is reserved.

Who it suits

It suits desktop builders and upgraders with a free PCIe 4.0 M.2 slot and existing cooling, and gamers who want a large, fast drive for their library. It is also compatible in principle with devices that accept a standard M.2 2280 NVMe drive, though you should confirm this for your own device.

What to check before you buy

• Slot type: confirm an M.2 slot with NVMe support and the standard 2280 length.
• PCIe generation: a PCIe 3.0 slot limits the speed; PCIe 4.0 runs at the full listed speed.
• Cooling: make sure the slot has a heatsink or cover, or plan to add one.
• Clearance: check the height available under any graphics card or cover.
• Operating system: the Game Mode feature is described for Windows.
• Data migration: back up your files and decide whether to clone or reinstall.

The short version

• A 2TB M.2 NVMe SSD using PCIe 4.0 x4.
• Sequential reads of up to 7,300 MB/s, as listed.
• Game Mode 2.0 for optimised Windows gaming performance.
• Sold without a heatsink, so it relies on your system's cooling.
• Best for desktops and builds with a free, cooled PCIe 4.0 M.2 slot.

Bloiq is reader-supported. Some links may earn us a commission; it never affects what we write. How we make money.