SanDisk 4TB SSD PCIe 4.0 NVMe M.2 2280

The WD Blue SN5100 is a 4TB PCIe 4.0 NVMe SSD with strong random performance but QLC NAND that limits sustained writes. It's pricey for what it is, sitting in the 18th percentile for affordability, though Canadian buyers can grab it for CAD 750 at Memory Express. The 5-year warranty and 1,200 TBW endurance are decent, but it's already been replaced by a newer generation. Buy it for capacity in a thin laptop, skip it for heavy write workloads.

Let's talk raw numbers first. The SN5100 is rated for 6,900 MB/s sequential reads and 6,700 MB/s writes. That puts it in the 84th percentile for speed among all drives we track, which is solid but not earth-shattering for PCIe 4.0. The random performance is where things get more interesting. 900K random read IOPS and 1,100K random write IOPS land it in the 94th percentile for random performance. That's genuinely impressive for a QLC drive, and it means everyday tasks like booting Windows, launching apps, and scrubbing through large photo libraries will feel snappy. The nCache 4.0 tech is doing real work here, using a portion of the drive as fast SLC cache to mask the inherent slowness of QLC NAND.

But here's the catch. QLC NAND has a reputation for falling off a cliff once you exhaust that cache. If you're copying a massive 500GB video project in one go, you'll likely see speeds drop dramatically after the cache fills. The 1,200 TBW endurance rating is decent for QLC, sitting at the 75th percentile, but it's nowhere near what you'd get from a TLC drive like the WD Black SN850X. For most people doing normal workloads, this won't matter. For video editors who hammer their drives daily, it absolutely will.

The SN5100 sits in an awkward spot between budget QLC drives and premium TLC options. The WD Black SN850X is the obvious step up. It uses TLC NAND, has a proper DRAM cache, and delivers better sustained performance. If you're doing heavy video editing or running a database, the SN850X is worth the extra cash. The Samsung 9100 PRO is another strong alternative, especially if you want top-tier random performance and Samsung's excellent software ecosystem. Both of those drives will outlast the SN5100 in endurance and hold their speeds better under sustained load.

On the budget side, the Crucial T500 and Kingston FURY Renegade G5 are worth a look. The T500 often undercuts the SN5100 on price while offering TLC NAND and comparable real-world performance. The FURY Renegade G5 is a bit more gaming-focused, with aggressive peak speeds and a flashy heatsink option. The Seagate FireCuda 530R is another PCIe 4.0 contender that trades blows with the SN5100 on speed but typically comes with better endurance ratings. If you're just looking for a big, fast game library drive, any of these will do the job. The SN5100's main advantage is that 4TB capacity in a single-sided form factor, which matters for thin laptops.

Here's where things get messy. The SN5100 is not cheap. In the US, it's listed at $520, which puts it in the 18th percentile for affordability. That's rough for a QLC drive, especially when TLC competitors are hovering around similar price points. In Canada, the spread is wild. We're seeing prices from CAD 750 all the way up to CAD 2,060 across four listings. That's a CAD 1,310 gap for the exact same drive. If you're shopping in Canada, Memory Express has the best deal at CAD 750, and honestly, anything above that is a hard pass. In Europe, the range is tighter but still notable, from EUR 560 to EUR 647. The EUR 560 listing is the one to grab if you're in Germany, Spain, France, or Italy.

For a 4TB PCIe 4.0 drive, $520 isn't outrageous in a vacuum. But when you factor in the QLC NAND and the fact that this drive has already been replaced in the product lineup, the value proposition gets shaky. You're paying a premium for capacity while sacrificing endurance and sustained write performance. If you can find it on sale near the lower end of those international price ranges, it starts to make more sense.

The WD Blue SN5100 is one of those drives that makes you do a double take. It's a 4TB PCIe 4.0 NVMe SSD with QLC NAND, and on paper it looks like a budget-friendly way to stuff a ton of storage into a laptop or desktop. But the moment you dig into the details, things get a little weird. The product page literally says it's been replaced by a newer generation, yet here it is, still sitting on shelves with a 5-year warranty and some genuinely impressive speed numbers. So what's the deal? We grabbed the spec sheet and ran it through our database to figure out who this drive is actually for in 2025.

Skip this drive if you do any kind of sustained write-heavy work. Video editors, 3D artists, and anyone who regularly moves hundreds of gigabytes at a time will hit the QLC cache wall and watch speeds plummet. The 1,200 TBW endurance rating is also a red flag for heavy users. If you're writing 100GB a day, you'll burn through that in about three years. Look at the WD Black SN850X or Samsung 9100 PRO instead. Both use TLC NAND and offer significantly better endurance.

Also skip it if you're building a portable external SSD. The portable use case score of 20.3 out of 100 is one of the worst we've seen. The drive runs hot under sustained load, and the QLC NAND doesn't handle the thermal constraints of a compact enclosure well. If you need a portable drive, get something designed for that purpose, like a TLC drive with a proper heatsink or a pre-built portable SSD.

If you need 4TB of fast storage in a thin laptop and you can find the SN5100 at the low end of its price range, it's a reasonable buy. The random performance is genuinely good, and for everyday use, you won't notice the QLC limitations. The 5-year warranty provides some peace of mind, and the single-sided design means it'll fit in almost any M.2 slot. At CAD 750 from Memory Express or EUR 560 in Europe, it's a solid deal for capacity-hungry users who don't push their drives hard.

But if you're a content creator, a data hoarder who moves massive files regularly, or someone who just wants the best performance per dollar, look elsewhere. The SN850X, 9100 PRO, or even the Crucial T500 will serve you better in the long run. The SN5100's QLC NAND and middling endurance make it a poor fit for sustained write-heavy workloads. And the fact that it's already been replaced in the product stack means firmware updates and long-term support are questionable.