Western Digital 4TB SSD PCIe 4.0 x4 NVMe M.2

The SN850X 4TB hits 7,300 MB/s sequential reads, putting it in the 94th percentile for speed, with a 2,400 TBW endurance rating that's well above average. It's expensive though, landing in the 8th percentile for affordability at $1,037 USD. Great drive if you need 4TB of fast storage, but overkill for casual use.

Sequential reads and writes are the headline here. 7,300 MB/s read and 6,600 MB/s write put this drive near the top of the PCIe 4.0 food chain. For context, that's fast enough to move a 100GB game install in roughly 15 seconds, assuming your motherboard and CPU can keep up. The 94th percentile speed ranking isn't just marketing fluff, it's backed up by the raw numbers.

Random performance is where things get more interesting. The 62nd percentile random score means this drive is solid but not exceptional when it comes to small file operations. If you're mostly gaming or doing large sequential transfers, you'll never notice. But if you're running a database or doing heavy mixed workloads, there are drives in this price range that handle random I/O better. The heatsink model helps keep sustained performance stable, though the listing notes this particular variant is the non-heatsink version, so plan on adding your own cooling if your motherboard doesn't have a built-in M.2 cover.

The Samsung 9100 PRO is the obvious rival here, and it trades blows with the SN850X on sequential speeds while typically offering better random performance. The Kingston FURY Renegade SFYRDK/4000G is another strong Gen 4 contender that often undercuts WD on price while matching the 7,300 MB/s read speed. The Crucial T500 and Micron T710 are both solid alternatives too, with the Crucial usually offering better value per gigabyte. Where the SN850X stands out is the combination of 4TB capacity, top-tier sequential speed, and that 2,400 TBW endurance rating. The SanDisk Black SN850X listing appears to be the same drive under different branding, so don't pay more for one over the other.

At $1,037 USD, you're paying roughly $0.26 per gigabyte. That's not outrageous for a 4TB Gen 4 drive with this speed rating, but it's also not a bargain. The INR listing at 99,000 and JPY listing at 145,940 both reflect the same premium positioning in their respective markets. The 8th percentile affordability score tells the story: this is a flagship product with flagship pricing. The 2,400 TBW endurance and 5-year warranty do add real value over the life of the drive, especially if you're the type who writes a lot of data. But if you're just looking for a game storage drive, there are cheaper 4TB options that will feel nearly identical in real-world use.

The SN850X 4TB hits 7,300 MB/s sequential reads, which puts it in the 94th percentile for speed in our database. That's about as fast as PCIe 4.0 gets before you jump to Gen 5 drives that cost even more and run hotter. The 4TB capacity also lands in the 93rd percentile, so you're getting a serious amount of room for game libraries, video projects, or whatever else you're hoarding.

But here's the catch. The affordability score sits at the 8th percentile, which is our polite way of saying this thing is expensive. At $1,037 USD for the US listing, you're paying a premium for that WD Black badge and the 4TB capacity. The endurance rating of 2,400 TBW is solid at the 83rd percentile, and the 5-year warranty helps soften the sticker shock a bit.

If you're on a budget, this drive is not for you. The 8th percentile affordability score means there are plenty of 4TB Gen 4 drives that cost significantly less while still delivering solid performance. Casual gamers who mostly play a handful of titles won't notice the difference between 7,300 MB/s and 5,000 MB/s in real-world load times. And if your workload involves heavy random I/O like database operations or virtualization, the 62nd percentile random performance means there are better options in this price range. The lack of an included heatsink on this variant is another reason to look elsewhere if you don't want to deal with aftermarket cooling.

The SN850X 4TB is a genuinely fast drive with excellent endurance and a capacity that most people won't outgrow anytime soon. The 94th percentile speed and 83rd percentile endurance make it a strong pick for anyone who wants a set-it-and-forget-it storage upgrade. But the 8th percentile affordability score means you need to actually use that speed and capacity to justify the cost. If you're building a high-end gaming rig or a workstation that handles large files regularly, this drive earns its keep. If you're just adding storage to an older system, you're paying for performance you'll never see.