The Amazon deal in this headline was reported on January 19, 2024: the 4TB WD_BLACK SN850X NVMe SSD, model WDS400T2X0E, was listed at $309.99 against a stated $699.99 reference price. That works out to $390 off, or about 55.7%. It is a historical price, not a verified current offer; no August 2026 price was established. The deal SKU also does not include a heatsink.
What the Amazon deal covered
The original deal page identified the product as the WD_BLACK SN850X 4TB NVMe SSD, model WDS400T2X0E, and reported the $309.99 Amazon price on January 19, 2024. Its $699.99 comparison price and claimed discount come from that page; they do not establish that $699.99 was the drive’s typical street price or that the offer was a lowest-ever price. See the original deal report.
The report is dated and does not verify a live Amazon listing or price in August 2026. Treat $309.99 as historical, not as a current buying benchmark.
What the 4TB SN850X offers
This is a high-end PCIe 4.0 x4 NVMe drive in the M.2 2280 format, using TLC 3D NAND. For the 4TB model, the manufacturer rates sequential reads at up to 7,300MB/s and writes at up to 6,600MB/s. It also lists up to 1.2 million random-read IOPS and 1.1 million random-write IOPS. These are manufacturer specifications, not guarantees of a particular game-loading time or sustained real-world write speed.
#1 Best Overall
- This product has been replaced by our latest generation. Please search for the SANDISK Optimus GX PRO 850X NVMe SSD
- TRANFORM YOUR PC: Insane speeds up to 7,300MB/s (1TB - 4TB models) deliver top-tier performance with ridiculously short load times for your gaming PC or workstation — for the elite experience you’ve been waiting for.
- MORE ROOM FOR MORE GAMES: Capacities up to 8TB built with SANDISK TLC 3D NAND, means you get to keep more games at the ready — and get into the action even faster.
The listed endurance is 2,400TBW, and the warranty is five years limited, subject to the manufacturer’s terms. The product supports Microsoft DirectStorage; WD_BLACK Dashboard software and Game Mode 2.0 are available for Windows. The 4TB figure is the drive’s class capacity, not the exact amount of formatted space an operating system will show.
Check the manufacturer’s 4TB product specifications and the SN850X data sheet for the detailed ratings.
Rank #2
- This product has been replaced by our latest generation. Please search for the SANDISK Optimus GX PRO 850X NVMe SSD
- TRANFORM YOUR PC: Insane speeds up to 7,300MB/s (1TB - 4TB models) deliver top-tier performance with ridiculously short load times for your gaming PC or workstation — for the elite experience you’ve been waiting for.
- MORE ROOM FOR MORE GAMES: Capacities up to 8TB built with SANDISK TLC 3D NAND, means you get to keep more games at the ready — and get into the action even faster.
- DO MORE WITH WD_BLACK DASHBOARD: The downloadable WD_BLACK Dashboard (Windows only) monitors your drive’s health, lets you customize your RGB lighting, and, exclusively on the SN850X SSD, enables Game Mode 2.0 to transform your gaming experience.
- FUTURE FORWARD FREATURES: The WD_BLACK SN850X SSD boasts a powerful suite of features, including Predictive Loading, Overhead Balancing, and Adaptive Thermal Management (ATM).
Where 4TB can be useful
- Gaming: Room for a large library of modern games without juggling installs.
- Creative work: Fast local storage for video footage, photo libraries, and active projects.
- Development and workstation use: Space for virtual machines, build environments, scratch files, and other large working sets.
- Consolidation: One large drive can replace several smaller drives when the system has a suitable slot.
Capacity alone does not make this the best-value choice for everyone. A smaller or less expensive PCIe 4.0 SSD may be sufficient for a boot drive or modest game library, and a high sequential benchmark does not mean games load proportionally faster.
Check the model number and heatsink before buying
The deal SKU, WDS400T2X0E, is the version without a heatsink. The separate heatsink-equipped 4TB model is WDS400T2XHE. Do not assume a listing for one is the other; confirm the complete model number in the product details.
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Rank #3
- This product has been replaced by our latest generation. Please search for the SANDISK Optimus GX 7100 NVMe SSD
- HIGH-OCTANE GAMING. Experience speeds up to 7,250MB/s read and 6,900MB/s write (1-2TB models), with up to 35% faster performance than previous generation.
- PURPOSE-BUILT. Designed for serious on-the-go gamers, with a PCIe Gen4 interface and SANDISK’s next generation TLC 3D NAND.
- MORE TIME TO CLEAR THAT CHECKPOINT. Built with laptops and handheld gaming devices in mind, with up to 100% more power efficiency over the previous generation. DO MORE WITH DASHBOARD. Ensure your drive is optimized for prime performance with the downloadable WD_BLACK Dashboard (Windows only).
- AMPLIFY YOUR CONTENT. Up to 2,400TBW endurance (4TB model) for gameplay streaming, speedrun captures, or creating with the latest game engines.
A desktop motherboard’s M.2 heatsink may be suitable, depending on the board and airflow. If the system lacks a suitable thermal solution, plan for one rather than assuming the bare drive includes it. The heatsink-equipped version is physically larger, so check clearance in a compact PC or laptop.
Compatibility by device
Desktop PCs
Confirm that the motherboard has an available M-key M.2 slot that accepts a 2280 NVMe drive. PCIe 4.0 x4 support is needed to approach the advertised performance. The SSD can work in compatible PCIe Gen3 systems, but the older interface limits speed; buying it for capacity or a future platform upgrade may still make sense, but paying a premium solely for Gen4 performance would not.
Rank #4
- TRANFORM YOUR PC: Insane speeds up to 7,300MB/s (1TB - 4TB models) deliver top-tier performance with ridiculously short load times for your gaming PC or workstation — for the elite experience you’ve been waiting for.
- MORE ROOM FOR MORE GAMES: Capacities up to 8TB built with SANDISK TLC 3D NAND, means you get to keep more games at the ready — and get into the action even faster.
- HEATSINK FOR THE WIN: The WD_BLACK SN850X NVMe SSD 1TB and 2TB drives have an optional heatsink version that not only looks awesome but also helps your rig maintain peak performance through the most intense gaming sessions.
- DO MORE WITH WD_BLACK DASHBOARD: The downloadable WD_BLACK Dashboard (Windows only) monitors your drive’s health, lets you customize your RGB lighting, and, exclusively on the SN850X SSD, enables Game Mode 2.0 to transform your gaming experience.
- FUTURE FORWARD FREATURES: The WD_BLACK SN850X SSD boasts a powerful suite of features, including Predictive Loading, Overhead Balancing, and Adaptive Thermal Management (ATM).
Laptops
Check the laptop’s service manual or manufacturer specifications before ordering. M.2 describes a physical connector family, not a guarantee that every slot supports NVMe: verify NVMe rather than SATA-only support, 2280 length, capacity support, and room for the module. Chassis clearance and thermal behavior can also constrain an upgrade. If replacing the boot drive, account for cloning or reinstalling the operating system and any recovery partitions.
PlayStation 5
Do not treat WDS400T2X0E as a plug-and-play PS5 choice: it has no heatsink. The manufacturer identifies the heatsink-equipped SN850X variant for PS5 use. Look for model WDS400T2XHE or another SSD and heatsink combination that meets the console’s fit and cooling requirements. See the manufacturer’s product page for the variant information.
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- This product has been replaced by our latest generation. Please search for the SANDISK Optimus GX PRO 850X NVMe SSD
- TRANFORM YOUR PC: Insane speeds up to 7,300MB/s (1TB - 4TB models) deliver top-tier performance with ridiculously short load times for your gaming PC or workstation — for the elite experience you’ve been waiting for.
- MORE ROOM FOR MORE GAMES: Capacities up to 8TB built with SANDISK TLC 3D NAND, means you get to keep more games at the ready — and get into the action even faster.
Is the SN850X still worth considering?
The SN850X remains a technically capable PCIe 4.0 drive. Its strongest case is combining 4TB-class capacity with high-end Gen4 performance, TLC NAND, substantial rated endurance, and a five-year limited warranty—not a promise that every application or game will become dramatically faster.
- Consider it if you need a large, fast NVMe drive, have a compatible M.2 slot, and the live price is competitive for the exact model and capacity.
- Compare lower-cost PCIe 4.0 options if gaming responsiveness or everyday use matters more than maximum benchmark speeds. A cheaper TLC drive may be adequate for those workloads.
- Compare premium PCIe 4.0 alternatives such as the Samsung 990 Pro if you are weighing enthusiast-class options; check the exact capacity and heatsink variant.
- Consider PCIe 5.0 for a compatible new build only if your workload and platform can use the additional sequential throughput.
- Choose another route if your system has no NVMe slot, needs an integrated heatsink for console use, or has no practical need for 4TB.
For any live listing, verify the seller, exact SKU, return terms, and regional warranty eligibility. Keep the invoice and check the manufacturer’s warranty and endurance guidance; the five-year limited warranty is subject to its terms and may depend on region and proof of purchase.
Quick Recap
Sources and product details
- Original January 19, 2024 Amazon deal report
- WD_BLACK SN850X 4TB product page
- SanDisk buying page for the WDS400T2X0E variant
- Manufacturer compatibility information
- Manufacturer product-family and software information
- Crucial T500 product page
- Tom’s Hardware SN850X review
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
