SanDisk 4TB SSD PCIe 4.0 NVMe M.2 2280

The WD Blue SN5100 is a 4TB PCIe 4.0 drive with strong random performance and solid sequential speeds, but QLC NAND means sustained writes will slow down. It's priced at the 18th percentile for affordability, so it's not cheap, and it's already been replaced by the Optimus 5100. Canadian buyers should target the CAD 689 price at Memory Express, while European buyers should look for EUR 560. It's a decent buy for gamers and general users at the right price, but content creators should look at TLC alternatives.

The headline numbers are solid. 6,900 MB/s sequential read and 6,700 MB/s write put this drive in the 85th percentile for speed, which means it's faster than most PCIe 4.0 drives out there but not quite at the top of the charts. For real-world use, that translates to copying a 100GB game folder in roughly 15 seconds, assuming your other drive can keep up. The random performance is where this drive actually shines though. 900K random read IOPS and 1,100K random write IOPS land it in the 94th percentile for random performance, which is genuinely impressive for a QLC drive.

The catch is the QLC NAND itself. QLC drives typically slow down dramatically once you fill them past about 75% capacity or when the SLC cache runs out during large sustained writes. The nCache 4.0 technology helps mask this by treating a portion of the drive as faster SLC cache, but on a 4TB drive, that cache can only do so much. If you're regularly moving hundreds of gigabytes at a time, you'll eventually hit the QLC wall and see speeds drop. For most people doing normal stuff, gaming, booting Windows, loading apps, you'll never notice. But if you're a video editor dumping 500GB of footage at once, you'll feel it.

The Samsung 9100 PRO is the obvious elephant in the room. It's newer, faster, and built on TLC NAND, which means it won't have the same sustained write slowdowns as this QLC drive. But it also costs more, and if you're mostly reading data rather than writing huge files constantly, the real-world difference might not justify the premium. The Kingston FURY Renegade is another strong option, with similar PCIe 4.0 speeds but typically better pricing and a more gaming-focused feature set. If you're building a gaming rig, the Renegade is probably the smarter buy.

The Crucial T500 and WD_BLACK SN850X are both TLC drives that compete directly on price and performance. The SN850X in particular is interesting because it's from the same family tree, Western Digital, but it's a TLC drive with better sustained performance and a more established reputation. The Micron T710 is also worth a look if you can find it at a good price. The SN5100's main advantage over all of these is that 4TB capacity at a potentially lower price point, but only if you catch it on sale. At full retail, the TLC competition is just better value.

Here's where things get messy. The affordability percentile is 18th, which means this drive is more expensive than 82% of comparable drives in our database. That's rough for a QLC drive that's already been superseded by a newer model. The US price sits at $520, which is a lot of money for a drive that will slow down under sustained writes.

The Canadian pricing is all over the place, ranging from CAD 689 to CAD 2,060 across four listings. That's a CAD 1,371 spread, which is frankly absurd. If you're in Canada, Memory Express has the best deal at CAD 689, and you should absolutely not pay anywhere near the CAD 2,060 end of that range. In Europe, prices range from EUR 560 to EUR 647 across four listings, a EUR 87 spread. Not as wild as Canada, but still worth shopping around. The EUR 560 price is the one to look for. At those lower prices, this drive starts to make more sense. At the higher end, you're getting fleeced.

The WD Blue SN5100 is a 4TB PCIe 4.0 NVMe drive that sits in a weird spot. It's got the capacity and the sequential speed to make it look like a high-end drive, but it's built on QLC NAND and priced like it's trying to be something it isn't. The product page itself is a bit confused too, it talks about 2TB max capacity in one breath and then sells a 4TB model in the next. Classic rebrand growing pains.

Who is this for? Honestly, it's for someone who needs a lot of fast storage in a laptop or desktop and doesn't want to think too hard about it. The 4TB capacity puts it in the 93rd percentile of all drives we track, which is a big deal if you're tired of juggling game installs or video projects. The 6,900 MB/s read and 6,700 MB/s write speeds are nothing to sneeze at either, landing it in the 85th percentile for speed overall.

But here's the thing. This drive is already being replaced by the Optimus 5100, according to the manufacturer's own page. So you're looking at a drive that's technically last-gen while still being sold at full price in some places. That's not automatically a dealbreaker, but it does mean you should pay attention to what you're actually getting for your money.

Content creators and anyone who regularly moves large files should look elsewhere. The QLC NAND means sustained write speeds will drop once the SLC cache is exhausted, which is exactly the scenario you hit when dumping 200GB of video footage or running large backups. The Samsung 9100 PRO or WD_BLACK SN850X are better choices for that workload, with TLC NAND that maintains performance under sustained writes.

Also skip this if you're looking for a portable drive. The portable use case score of 19.4 out of 100 is one of the worst we've seen, likely due to the QLC NAND and power characteristics not playing well with external enclosures. If you want a fast external drive, look at a TLC drive in a Thunderbolt enclosure instead. And if you're on a tight budget, the 18th percentile affordability ranking means there are plenty of cheaper 4TB options out there, even if they're not quite as fast on paper.

If you're a gamer or general user who wants 4TB of fast storage and you can find this drive at the lower end of its price range, it's a decent buy. The random performance is genuinely good, and for loading games and apps, you'll be happy with it. The 1,200 TBW endurance rating is also better than many QLC drives, so you don't need to worry about wearing it out with normal use.

But if you're a content creator who regularly moves large files, or if you're building a system where sustained write performance matters, look elsewhere. The QLC NAND will bite you when the cache runs out, and at the 18th percentile for affordability, you're paying a premium for a drive that has a known weakness. The TLC alternatives from Samsung, Kingston, and even Western Digital's own SN850X are better choices for that kind of workload. And if you're in Canada, do not pay more than CAD 689 for this drive. Seriously.