Storage FOMO Is Real: As Prime Day Fades, the Time to Buy a 2TB, 4TB, or 8TB SSD Is Right Now

Maybe you’ve been waiting for your budget to have just enough of a cushion, or for that hard drive or boot SSD to finally fill up. Or maybe tariff threats have you uncertain about buying anything tech, period. Sure, you can put off that storage upgrade a bit longer—but we’d advise against it. 

All week, PCMag’s storage-expertise braintrust, Tom Brant, John Burek, and Tony Hoffman, have been looking at the Prime Day sales, and we’ve come to one joint conclusion: If you need a multi-terabyte SSD—an internal drive or an external USB one—you may look back at this Prime Day as a small, golden window of time when you could have scored a proper mega-deal. That’s especially true this year, when, all of a sudden, attractive SSDs greater than 1TB in capacity are seeing some really aggressive price cuts.

The Premium for Going Big

The thing is, for years, the budget-buy action in SSDs was largely confined to internal and external drives in the 240GB/256GB, 500GB/512GB, and 960GB/1TB storage capacities. At a certain point above 1TB—for a while, it was 2TB, and more recently, 4TB and 8TB—you would pay a premium in terms of cost per gigabyte for an SSD. That’s important to bear in mind: SSDs are much less about the overall cost than the cost per gigabyte, which you calculate by dividing the capacity in gigabytes by the price. (For ease of calculation, you can assume 1TB is about 1,000 gigs, though it’s really a smidge more.) Cost per gig is the best gauge of the true value of the drive’s hardware, assuming you set aside features like ruggedness, included software, hardware encryption, and warranty.

And most of the time, you can. Today, most mainstream SSDs for consumers are durable enough for everyday workloads, leaving scant risk of “writing one to death.” The cost per gig really is an excellent yardstick to use, assuming most else is equal. Prime Day 2025 is even serving up some bargains in the rarefied 8TB SSD tier, which is the highest capacity you’ll find in a single-drive mainstream SSD. 

(Credit: Joseph Maldonado)

Will hefty tariffs affect the prices of storage sourced from South Korea (home of flash-memory giant Samsung), China, and Southeast Asia? Only time will tell. But right now, as Prime Day is winding down, the SSD deals are still going strong. In PC Labs, we’ve tested one flavor or another of most of the drives on sale, so we have some advice.

This Year, the M.2 Internal SSD Deals Rule

Gumstick-shaped M.2 SSDs are today’s mainstream kind of internal drives. You’ll want to make sure your PC—laptop or desktop—can actually take a PCI Express M.2 drive. (Modern desktop motherboards usually have a slot or three, but check for specific PCIe M.2 compatibility.) Laptops are thornier, so check in with tech support from your laptop maker before diving in, because if you can change out the drive, it’ll likely have to be a new boot drive. And that requires an OS install or cloning the existing drive.

Any 8TB M.2 SSD has been a rare, expensive bird, but seeing one here from a major maker in the $500 zone is groundbreaking. That capacity is especially compelling if you have only one M.2 slot to fill, and you need to make the most of it. A 4TB or 8TB M.2 installed as a secondary drive in a desktop is also attractive as fast supplemental storage for the media files or PC games you access the most.

Here’s a rundown of the best multi-terabyte M.2 internal SSDs we found on sale in the heat of 2025 Prime Day. We’ve got reviews of most to back them up, too, so hit those links to dig deeper into models you may be considering. (Also, don’t miss out on any of the other savings. Make sure to keep an eye on our roundup of the Best Prime Day 2025 Deals.)

Our Prime Day Pick for an 8TB M.2 SSD

The WD Black SN850X is blazing fast for a PCI Express 4 SSD and put up exemplary results in our benchmark testing. At the time I reviewed its 2TB version, it was only available in capacities up to 4TB. An 8TB version is now available, and this Prime Day, it’s available for 40% off its list price. At its deal price of $545, its cost per gigabyte comes to 6.6 cents, a great rate for an elite PCIe 4 SSD of such massive capacity.

The SN850X awed us in our benchmark testing, posting top-tier throughput results in Crystal DiskMark testing, as well as a new high score in Crystal DiskMark’s 4K Write test. It turned in the second-highest score at the time in PCMark 10’s Overall Storage test, and it set a high score, which still stands, for a PCI Express 4 SSD in 3DMark Storage, a benchmark that aggregates the results of a series of gaming-related tasks. The SN850X is great for gamers who want a high-performance Gen 4 stick that can also hold a substantial game library, or content creators needing to quickly process myriad photos or high-res video. This Prime Day deal gives you a chance to acquire one of our favorite elite PCI Express 4 SSDs at a monstrous capacity for a very competitive price. 

Our Prime Day Pick for a 4TB M.2 SSD

The Crucial P310 is a versatile SSD offered in a full-size 80mm variant for laptop and desktop PC upgrades and an exceptionally compact 30mm version designed to fit handheld gaming consoles such as the Steam Deck. Performance-wise, the P310 2280 proves itself capable, with average results among the PCI Express 4.0 speedsters that we compared it with in our review. 

Overall, we found it to be a solid SSD, albeit a little pricey for the performance on offer. Prime Day significantly changes that, with a massive discount on the 4TB version of this SSD. Normally $333.99, you can get it for just $199.99 right now (5 cents per gigabyte) if you hurry. 

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Our Two Prime Day Picks for 2TB M.2 SSDs

The WD Black SN8100 is simply the fastest and most complete internal SSD that we have ever reviewed. It not only chalked up the highest Crystal DiskMark throughput and 4K read scores of any SSDs we have tested, it easily set a record high in our PCMark10 Overall Storage testing, and it narrowly missed out on a high score in the 3DMark Storage gaming-centric benchmark. WD/Sandisk includes a free download of Acronis True Image backup and migration software with the purchase of the SN8100. Also, the SN8100 meets the TCG/Opal V2.02 security standard, which supports AES hardware-based encryption for self-encrypted devices. The drive’s exceptional overall performance, power efficiency, software, and security earned it an Editors’ Choice award as a high-performance internal SSD and a rare 5-star rating.

As a PCI Express 5 SSD, the SN8100 requires specialized hardware to achieve its exemplary performance, but it is optimized for energy conservation, and, unlike most of its Gen 5 brethren, doesn’t require a massive heat dissipation solution–it can make do with a compact heatsink (not included). While the SN8100 is normally a premium-priced SSD, for Prime Day, Amazon is selling the 2TB stick that we reviewed for $189 (9 cents per gigabyte), 40% off its $319.99 list price, making it an appealing bargain for those who want the ultimate in Gen 5 performance at a relatively modest price.

The SSD 990 EVO Plus, an enhanced version of the Samsung SSD 990 EVO to which we gave a PCMag Editors’ Choice in our review, is on sale this Prime Day for just $113.99, 36% off its $176.99 list price, for a very appealing 5.7 cents per gigabyte. Like the SSD 990 EVO, the SSD 990 EVO Plus uses DRAM-less architecture, which keeps its price down and improves power efficiency. The EVO Plus provides a substantial increase in its throughput speeds over the standard SSD 990 EVO, with rated 7,250MBps and 6,300MBps sequential read and write speeds, respectively.

The SSD 990 EVO performed very well compared with similarly priced PCI Express 4 drives in our benchmarking, Samsung includes its Samsung Magician suite of SSD optimization tools, which allows you to streamline the data migration process for SSD upgrades, and protects data, monitors drive health, and provides firmware updates. It also supports AES 256-bit full-disk hardware encryption, and meets the TCG/Opal V2.0 security standard for self-encrypted devices. With the Samsung SSD 990 EVO Plus, you get essentially the same drive but with faster rated throughput speeds, and you can now have it for a compellingly low price.

The 2TB and 4TB External SSDs on Sale Are Not Bad, Either

Moving multiple terabytes over a USB interface can be a bit slow, even with an SSD, versus an internal PCI Express connection. But an external SSD is still a far sight faster than any external hard drive. And if you want an off-site backup that you can easily lock in a drawer or a safe, a 2TB or 4TB SSD is a great, cheap peace-of-mind solution. One or two drives on sale (not cited here) do even have biometric features that let you lock down the data with the likes of a fingerprint.

Our Two Prime Day Picks for 4TB External SSDs

Most PCs don’t have the requisite 20Gbps USB Gen 2×2 interface to get the actual potential peak speed of this very fast, premium SSD. But it doesn’t matter; it’s still a great deal even if you just have an ordinary USB 3.2 Gen 2 port with a USB-C connector. We gave the T9 Portable SSD 4.5 stars in our review, and the small, light Samsung external drive exhibited both superior speed and excellent anti-drop resistance. (It’s rated to shrug off falls of just under 10 feet.) It’s easily grippable and has a simple, clean design. Most of all, though, the cost-per-gig calculus here makes this our favorite performance-minded external-SSD choice for this Prime Day, by a long shot. When we tested it, it cost 11 cents per gig for the 4TB version; here, it’s down to 6.6 cents per gig.

Plus, this is a premium package through and through. The T9 supports 256-bit AES hardware-based encryption, the gold standard of civilian encryption solutions. Samsung’s software suite is also tops in the field, with detailed drive-monitoring and data-migration functionality. You get both kinds of cables you might possibly need in the box (USB-A and USB-C). And a five-year warranty, par for the course for a high-end external SSD, delivers peace of mind.

The T7 is a tiny, handy storage device with solid performance for its class. Its strong password-protected encryption should be more than adequate to protect your data. Samsung provides both a USB-C cable and a Type-C-to-A cable in the box. The latter is a thoughtful addition, since it means you won’t need to buy an adapter or dongle if you’re connecting the device to a rectangular USB Type-A port.

When we tested the T7, we found it to be a cost-effective choice as a mainstream pocket SSD, whether for a business traveler or for housing a home media library. And right now, it’s even more cost-effective, at just $218.49 for the 4TB version, down from $344.99. With a cost per gigabyte of just over 5 cents, you won’t find a better deal on a stellar external SSD.

Our Prime Day Pick for a 2TB External SSD

The Crucial X9 Pro has most everything users might look for in an external SSD: a compact and lightweight frame that’s also sturdy, 256-bit hardware-based encryption, and solid benchmark results in our tests. The X9 Pro has some ruggedness cred, with an Ingress Protection (IP) rating of IP55. This indicates that the drive is certified to provide water and dust resistance. 

The X9 Pro comes preformatted in the exFAT file format, and works out of the box with Windows, Mac, Android, iPad, PC, Linux, Xbox, and PlayStation. Concerned about longevity? The X9 Pro comes with a five-year warranty, a generous span when many external-drive manufacturers stop at three years.

The 2TB version of this drive is normally $179.99, but is marked down to $119.99 for Prime Day, which translates to a cost of 6 cents per gigabyte. Snap one up before they sell out!

Best Tips for Prime Day 2025

About Tony Hoffman

Senior Analyst, Hardware

Since 2004, I have worked on PCMag’s hardware team, covering at various times printers, scanners, projectors, storage, and monitors. I currently focus my testing efforts on 3D printers, pro and productivity displays, and drives and SSDs of all sorts.

Over the years, I have reviewed iPad and iPhone science apps, plus the occasional camera, laptop, keyboard, and mouse. I’ve also written a host of articles about astronomy, space science, travel photography, and astrophotography for PCMag and its past and present sibling publications (among them, Mashable and ExtremeTech), as well as for the PCMag Digital Edition.

Read Tony’s full bio

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About John Burek

Executive Editor and PC Labs Director

I have been a technology journalist for 30-plus years and have covered just about every kind of computer gear—from the 386SX to 64-core processors—in my long tenure as an editor, a writer, and an advice columnist. For almost a quarter-century, I worked on the seminal, gigantic Computer Shopper magazine (and later, its digital counterpart), aka the phone book for PC buyers, and the nemesis of every postal delivery person. I was Computer Shopper’s editor in chief for its final nine years, after which much of its digital content was folded into PCMag.com. I also served, briefly, as the editor in chief of the well-known hard-core tech site Tom’s Hardware.

During that time, I’ve built and torn down enough desktop PCs to equip a city block’s worth of internet cafes. Under race conditions, I’ve built PCs from bare-board to bootup in under 5 minutes.

In my early career, I worked as an editor of scholarly science books, and as an editor of “Dummies”-style computer guidebooks for Brady Books (now, BradyGames). I’m a lifetime New Yorker, a graduate of New York University’s journalism program, and a member of Phi Beta Kappa.

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About Tom Brant

Deputy Managing Editor

I’m the deputy managing editor of the hardware team at PCMag.com. Reading this during the day? Then you’ve caught me testing gear and editing reviews of laptops, desktop PCs, and tons of other personal tech. (Reading this at night? Then I’m probably dreaming about all those cool products.) I’ve covered the consumer tech world as an editor, reporter, and analyst since 2015.

I’ve evaluated the performance, value, and features of hundreds of personal tech devices and services, from laptops to Wi-Fi hotspots and everything in between. I’ve also covered the launches of dozens of groundbreaking technologies, from hyperloop test tracks in the desert to the latest silicon from Apple and Intel.

I’ve appeared on CBS News, in USA Today, and at many other outlets to offer analysis on breaking technology news.

Before I joined the tech-journalism ranks, I wrote on topics as diverse as Borneo’s rain forests, Middle Eastern airlines, and Big Data’s role in presidential elections. A graduate of Middlebury College, I also have a master’s degree in journalism and French Studies from New York University.

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