Western Digital WD_BLACK SN7100

The WD Black SN7100 is a 4TB PCIe 4.0 drive with 95th percentile random performance and solid endurance. It's fast, reliable, and great for laptops and gaming rigs. Just make sure you don't overpay, pricing is all over the map right now.

Sequential reads top out at 7,250 MB/s and writes at 6,900 MB/s, which puts it in the 90th percentile for speed overall. Random performance is the real story here: 1,000K read IOPS and 1,400K write IOPS land it at the 95th percentile, meaning it's one of the best on the market for scattered small-file workloads. The TLC NAND and DRAM-less design don't seem to hurt real-world performance much, though sustained writes under heavy load might dip more than a drive with dedicated cache. One buyer tested their 4TB unit and got 7,052 MB/s read and 6,487 MB/s write, slightly below spec but still blazing fast.

Against the Samsung 990 PRO, the SN7100 actually holds its own on random performance, which is impressive given the Samsung has DRAM. The Micron T710 and Seagate FireCuda 530R are both strong competitors, but the WD Black's 4TB capacity at this speed tier gives it an edge for gamers who want one big drive. The Kingston Fury Renegade 4TB is probably the closest direct rival, and it trades blows depending on workload. The SanDisk WD_BLACK SN8100 is essentially a sibling product, so if you see that cheaper, grab it instead. The SN7100's main weakness is that DRAM-less design, which the 990 PRO and FireCuda 530R don't have to worry about.

Here's the thing: this drive is excellent, but the price spread is nuts. In Canada, you'll see it listed anywhere from CAD 850 to CAD 1,900 across three listings. That's a CAD 1,050 gap for the same drive. In the US, it's USD 625 to 677 across two listings, which is much tighter. One reviewer said it was originally $350 and is nowhere near worth the current cost, suggesting $580 or under as a reasonable buy point. If you can find it at the lower end of that CAD range or under USD 600, it's a solid deal. At the high end, you're paying flagship money for a drive that should cost less.

The WD Black SN7100 is a 4TB PCIe 4.0 drive that hits 7,250 MB/s reads and 6,900 MB/s writes. It's DRAM-less, which sounds like a corner cut, but the numbers tell a different story. This thing lands in the 95th percentile for random performance in our database, so the lack of a DRAM chip isn't holding it back much.

It's built for gamers who want a big, fast drive without paying flagship prices. The 1,200 TBW endurance rating and 5-year warranty give it some staying power too. But the pricing is all over the place right now, and that's where things get interesting.

Skip this if you're building a portable external drive. The portable score is a dismal 22.8 out of 100, so this belongs inside a desktop or laptop, not in an enclosure bouncing around in a bag. Also skip it if you're on a tight budget and don't need 4TB, there are cheaper 1TB and 2TB options that deliver similar real-world performance for most people. And if you're doing heavy sustained writes like 8K video editing all day, a DRAM-equipped drive like the Samsung 990 PRO will hold up better under constant load.

If you're a gamer or content creator who needs 4TB of fast NVMe storage and you find this at a reasonable price, buy it. The random performance is genuinely top-tier, and the endurance rating means it'll last through years of game installs and file churn. It's especially good for laptop users, scoring 87.3 out of 100 in that category. Just don't overpay. This drive is great, but it's not worth CAD 1,900 or USD 677 when the same silicon is available for way less if you shop around.