Inside modern laptops, and in the hollows of today's desktop-PC motherboards, you'll find little sticks of storage—M.2 solid-state drives—that are far smaller and faster than classic 2.5-inch SATA SSDs and spinning hard drives. At PCMag, we have been reviewing SSDs since the late 1990s, and M.2 SSDs since their introduction over a decade ago. We subject each drive to speed tests using our rigorous, repeatable benchmarks, and also evaluate them based on rated endurance, features, bundled software, and value. Here, you'll find our top-rated M.2 SSDs according to PC Labs testing. Our current top basic M.2 SSD for most users is Crucial's P3, for its balance of speed, capacity, and price; for performance upgrades, we suggest WD's Black SN850X. Beyond these SSDs, we offer additional vetted options for specific needs, accompanied by detailed guidance on selecting the best M.2 SSD for your PC. M.2 SSDs can be a little complicated, but we've got you covered.
Overview
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![Crucial P3]()
Best PCI Express 3.0 M.2 SSD for Most UsersCrucial P3
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![WD Black SN850X]()
Best PCI Express 4.0 M.2 SSD for Most UsersWD Black SN850X
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![WD Black SN8100]()
Best PCI Express 5.0 M.2 SSD for Most UsersWD Black SN8100
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![Addlink AddGame A93]()
Best Budget PCI Express 4.0 M.2 SSDAddlink AddGame A93
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![Crucial T500]()
Best PCI Express 4.0 M.2 SSD for Sheer SpeedCrucial T500
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![TeamGroup MP44]()
Best PCI Express 4.0 M.2 SSD for Peak CapacityTeamGroup MP44
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![Samsung SSD 990 Pro With Heatsink]()
Best PCI Express 4.0 M.2 SSD for Creative ProsSamsung SSD 990 Pro With Heatsink
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![Acer Predator GM7000]()
Best PCI Express 4.0 M.2 SSD for PS5 UpgradesAcer Predator GM7000
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![WD Blue SN5100]()
Best Energy-Efficient PCI Express 4.0 M.2 SSDWD Blue SN5100
You Can Trust Our Reviews
Deeper Dive: Our Top Tested Picks
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![Crucial P3]()
Best PCI Express 3.0 M.2 SSD for Most UsersCrucial P3
Pros & Cons
Why We Picked It
The Crucial P3 is a solid choice as a PCI Express 3.0 SSD to upgrade your system, providing good performance at such at a modest price. As the successor to the Crucial P2, the P3 offers higher capacities and much higher throughput speeds at a lower cost per gigabyte, thanks to Micron's switch from TLC to QLC flash memory for this drive. The drawback is that the change lowers the P3's write-durability rating, making it best for tasks that don't consistently write huge amounts of data to the drive, day in and day out. The controller lacks a DRAM cache, which causes a performance hit on some SSDs, especially with large file transfers, but the P3 generally scored well in the PCMark 10 benchmarks.
Who It's For
Users with older PCs: The Crucial P3 provides good performance in a PCI Express 3.0 NVMe SSD. Its QLC NAND flash memory keeps the P3's price down while allowing capacities up to 4TB. It's a spot-on pick for upgrading older PCs that don't support PCIe 4.0.
Bargain hunters: The Crucial P3 is a cost-effective SSD option for users who don't need the latest SSD speed, thanks to its PCI Express 3.0 interface and QLC NAND flash memory. Though it won't set any speed records, it performed well for a PCIe 3.0 SSD in our benchmarks.
Specs & Configurations
Bus Type PCI Express 3.0 x4 Capacity (Tested) 2 Controller Maker Phison Interface (Computer Side) M.2 Type-2280 Internal Form Factor M.2 Type-2280 Internal or External Internal NAND Type QLC NVMe Support Rated Maximum Sequential Read 3500 Rated Maximum Sequential Write 3000 Terabytes Written (TBW) Rating 440 Warranty Length 5 Learn More Crucial P3 Review -
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![WD Black SN850X]()
Best PCI Express 4.0 M.2 SSD for Most UsersWD Black SN850X
Pros & Cons
Why We Picked It
The WD Black SN850X is an upgrade to Sandisk's high-performance PCI Express 4.0 NVMe internal gaming SSD, the SN850. The SN850X improves on an already excellent drive by giving buyers the option for a 4TB version and an upgrade in flash memory technology that boosts sequential read and write speeds. It turned in improved benchmark results in both gaming and general storage tests (including a stellar score on the 3DMark Storage benchmark). You'll definitely want to use a heatsink with this speedster; it's available with or without one. About all it lacks is hardware-based security.
Who It's For
Upgraders seeking a balance of speed and capacity: The SN850X proves its mettle with impressive scores for a PCIe 4.0 SSD in both our general storage (PCMark 10 Overall Storage) and gaming-centric (3DMark Storage) benchmark tests. Now available in capacities up to 8TB, the SN850X can host a large media or game library.
Gamers: The SN850X has real gaming prowess for a PCI Express 4.0 SSD. It tallied a sky-high score for a PCIe 4.0 stick on the 3DMark Storage benchmark, which aggregates a drive's scores on various gaming-related tasks, such as installing and loading games, and saving their progress. It is available in 4TB and 8TB versions, enabling you to host a massive gaming library with room to spare.
Specs & Configurations
Bus Type PCI Express 4.0 Capacity (Tested) 2 Controller Maker SanDisk Interface (Computer Side) M.2 Type-2280 Internal Form Factor M.2 Type-2280 Internal or External Internal NAND Type TLC NVMe Support Rated Maximum Sequential Read 7300 Rated Maximum Sequential Write 6600 Terabytes Written (TBW) Rating 1200 Warranty Length 5 Learn More WD Black SN850X Review -
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Credit: Joseph Maldonado
![WD Black SN8100]()
Best PCI Express 5.0 M.2 SSD for Most UsersWD Black SN8100
Pros & Cons
Why We Picked It
Sandisk's WD Black SN8100, our latest internal-SSD speed champ, chalked up the highest Crystal DiskMark sequential throughput and 4K read scores of any SSDs we have tested, and it set a record high in our PCMark 10 Overall Storage testing, which measures a drive's speed in performing a variety of everyday storage tasks. It also fell just short of a best-ever score on the 3DMark Storage gaming-centric benchmark. Additionally, the SN8100 is power-efficient and does not require a large active heatsink, unlike some of its competitors.
Who It's For
Gamers: The SN8100 holds the record for the highest sequential read and write scores we've ever seen in Crystal DiskMark testing, and a near-record score in the gaming-centric 3DMark Storage benchmark. You will need a rig with a PCIe 5.0 M.2 slot, though, to make it worthwhile. Since we reviewed the SN8100, Sandisk has added a version of the drive with a compact heatsink as well as an 8TB version of the drive, which should hold a trove of AAA games.
Content creators: The SN8100 outperforms all previous SSDs we have reviewed in the Adobe Photoshop and Premiere Pro launch trace tests of the PCMark 10 benchmark. Its 4TB and 8TB versions should ensure that you have all the room you need for storing and working with video files.
Specs & Configurations
Bus Type PCI Express 5.0 Capacity (Tested) 2 Controller Maker Silicon Motion Interface (Computer Side) M.2 Type-2280 Internal Form Factor M.2 Type-2280 Internal or External Internal NAND Type TLC NVMe Support Rated Maximum Sequential Read 14900 Rated Maximum Sequential Write 14000 Terabytes Written (TBW) Rating 1200 Warranty Length 5 Learn More WD Black SN8100 Review -
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![Addlink AddGame A93]()
Best Budget PCI Express 4.0 M.2 SSDAddlink AddGame A93
Pros & Cons
Why We Picked It
The budget-friendly Addlink AddGame A93 PCI Express 4.0 internal SSD matched its rated throughput speeds and performed well against other PCIe 4.0 SSDs in our benchmark tests. The A93 meets Sony's requirements for use with the PlayStation 5, thanks in part to a compact heatsink that fits the M.2 expansion slot of the console. It has good durability ratings, and comes in capacities of up to 4TB. Its lack of DRAM could affect its performance in sustained large-file transfers, but that won’t be a problem for many users.
Who It’s For
Gamers: The A93 proved its mettle on the gaming-centric 3DMark Storage benchmark, turning in results typical of a PCI Express 4.0 speedster. It comes with an attached heatsink, which should help ward off thermal throttling if you use it in a desktop rig that lacks a motherboard heatsink.
Sony PS5 users: The AddGame A93 meets Sony's criteria for SSDs that can be used in the spare (secondary) M.2 slot of a PlayStation 5 while coming in at a relatively modest price. This includes a heatsink affixed to the top of the drive that is compact enough that the A93 should fit into a PS5's chassis with millimeters to spare.
Bargain hunters: The Addlink AddGame A93 is a great choice for budget-conscious users seeking a high-performance, general-purpose PCI Express 4.0 SSD. It boasts one of the better scores for a PCIe 4.0 SSD on the PCMark 10 overall storage test, and its score on the 3DMark Storage gaming-centric benchmark is typical of a PCIe 4.0 drive with a high rated speed.
Specs & Configurations
Bus Type PCI Express 4.0 Capacity (Tested) 4 Controller Maker Maxio Technology Interface (Computer Side) M.2 Type-2280 Internal Form Factor M.2 Type-2280 Internal or External Internal NAND Type TLC NVMe Support Rated Maximum Sequential Read 7400 Rated Maximum Sequential Write 6500 Terabytes Written (TBW) Rating 3000 Warranty Length 5 Learn More Addlink AddGame A93 Review -
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Credit: Joseph Maldonado
![Crucial T500]()
Best PCI Express 4.0 M.2 SSD for Sheer SpeedCrucial T500
Pros & Cons
Why We Picked It
The Crucial T500 is a step up from the company's P5 Plus, with a memory and processor upgrade and a boost in throughput speed. The T500 performed superbly against other elite PCI Express 4.0 SSDs in our benchmark testing, posting excellent results in both general storage and gaming tests. Micron offers versions of the 1TB and 2TB stick with an integrated heatsink, which adds just $10 to the bare drive's price at either capacity. The heatsink-equipped T500 plays well with the Sony PlayStation 5, meets the TCG Opal security standard, and comes with useful software.
Who It’s For
Upgraders: The Crucial T500 is for users willing to pay a little extra to get the best PCI Express 4.0 SSD performance. Its results in both the PCMark 10 Overall general-storage and 3DMark Storage gaming-centric benchmarks are superb.
Gamers: As noted, the T500 served up impressive results on the 3DMark Storage gaming-oriented test, and you can configure it with a compact heatsink. Unlike many recent M.2 SSDs, the T500 has a full DRAM cache (as well as a top-shelf Phison controller and 232-layer TLC NAND flash), which could give it an advantage in sustained large-file transfers, as well as in use with the PS5.
Specs & Configurations
Bus Type PCI Express 4.0 Capacity (Tested) 2 Controller Maker Phison Interface (Computer Side) M.2 Type-2280 Internal Form Factor M.2 Type-2280 Internal or External Internal NAND Type TLC NVMe Support Rated Maximum Sequential Read 7400 Rated Maximum Sequential Write 7000 Terabytes Written (TBW) Rating 1200 Warranty Length 5 Learn More Crucial T500 Review -
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![TeamGroup MP44]()
Best PCI Express 4.0 M.2 SSD for Peak CapacityTeamGroup MP44
Pros & Cons
Why We Picked It
The TeamGroup MP44 is one of the few PCI Express 4.0 M.2 SSDs available in capacities up to a whopping 8TB, though you do pay a premium per gigabyte at that capacity. The MP44, a DRAM-less internal SSD equipped with a graphene heat spreader, demonstrated its capabilities in general storage tasks, achieving a notable score in our PCMark 10 Overall benchmarking test. Its durability rating is among the highest we have seen on an M.2 SSD.
Who It's For
Upgraders: Whether it's general performance, capacity, or both that you're looking for, the TeamGroup MP44 has your back. It achieved a great score in the PCMark 10 Overall benchmark, which measures an SSD's performance in a range of everyday storage tasks, for a PCI Express 4.0 SSD.
Capacity hounds: While many SSD makers have claimed that they have an 8TB version of their M.2 SSD in the works, Teamgroup is one of the few that has actually delivered. (Look out also for the 8TB version of the WD Black SN850X when it's on sale.) This makes it a good fit for both content creators and users who want more space for a game or media library. While we love the fact that the TeamGroup MP44 is available in capacities up to 8TB, the cost per gigabyte at that capacity makes it best for well-heeled shoppers with a lot of data to store. Its high durability rating makes it a good choice for users who frequently write and overwrite scads of data.
Specs & Configurations
Bus Type PCI Express 4.0 Capacity (Tested) 2 Controller Maker Maxio Technology Interface (Computer Side) M.2 Type-2280 Internal Form Factor M.2 Type-2280 Internal or External Internal NAND Type TLC NVMe Support Rated Maximum Sequential Read 7400 Rated Maximum Sequential Write 7000 Terabytes Written (TBW) Rating 2500 Warranty Length 5 Learn More TeamGroup MP44 Review -
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![Samsung SSD 990 Pro With Heatsink]()
Best PCI Express 4.0 M.2 SSD for Creative ProsSamsung SSD 990 Pro With Heatsink
Pros & Cons
Why We Picked It
The Samsung SSD 990 Pro, the company's flagship PCI Express 4.0 NVMe internal solid-state drive, has a hard act to follow in the Editors' Choice-winning SSD 980 Pro, but for the most part it makes a great product even better. This power-efficient drive gets high marks for raw speed, everyday application performance, a strong software suite, and hardware-based encryption.
The heatsink-equipped version of this drive performed slightly better than the non-heatsink version (which we tested using our testbed's motherboard's heatsink) in most of our benchmarks. It doesn't quite merit the SSD 980 Pro's Editors' Choice award, as other recent internal SSDs have outpaced it in our gaming benchmarks. However, its overall capability makes this Samsung a versatile drive well-suited for creative tasks.
Who It's For
Upgraders: The SSD 990 Pro is a thoroughbred workhorse for both routine and creative tasks, and one of the top scorers among PCIe 4.0 SSDs on PCMark 10 Overall Storage, a benchmark that aggregates a drive's results in a variety of common storage tasks. It's an appealing choice and a worthy upgrade from the SSD 980 Pro, as well as midrange PCI Express 4.0 SSDs.
PS5 gamers: The Samsung SSD 990 Pro version we tested comes with an attached aluminum heatsink, which is compact enough to fit the drive and heatsink together in the secondary M.2 slot of a PlayStation 5. Even better, it meets Sony's criteria for PS5 friendliness. Its scores on the 3DMark Storage gaming-centric benchmark are typical of an elite PCIe 4.0 stick on the gaming-centric 3DMark Storage test, which we run on a Windows PC.
Specs & Configurations
Bus Type PCI Express 4.0 Capacity (Tested) 2 Controller Maker Samsung Interface (Computer Side) M.2 Type-2280 Internal Form Factor M.2 Type-2280 Internal or External Internal NAND Type MLC NVMe Support Rated Maximum Sequential Read 7450 Rated Maximum Sequential Write 6900 Terabytes Written (TBW) Rating 600 Warranty Length 5 Learn More Samsung SSD 990 Pro With Heatsink Review -
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![Acer Predator GM7000]()
Best PCI Express 4.0 M.2 SSD for PS5 UpgradesAcer Predator GM7000
Pros & Cons
Why We Picked It
The Acer Predator GM7000, the first PCI Express 4.0 NVMe SSD in the company's Predator line, is every bit as lethal as its gaming laptop and monitor brandmates. In addition to compatibility with a desktop or laptop computer, the GM7000 easily meets Sony's specs for use as a secondary drive for the PlayStation 5; Acer offers an optional aluminum heatsink that is compact enough for PS5 use.
In PC use, it tallied some of the faster throughput speeds we have seen in a single consumer-grade PCI Express 4.0 SSD, and it performed well in both our general storage and gaming benchmark tests. The Predator offers 256-bit AES encryption and includes a download card for a free custom version of Acronis True Image data cloning and backup software.
Who It's For
PS5 gamers: The GM7000 meets Sony's specifications for use as a secondary drive for a PlayStation 5. It comes with a graphene heat spreader, and Acer also offers an aluminum heatsink that is compact enough for use with the PS5.
Upgraders: The Acer Predator GM7000 is a versatile and feature-rich high-performance PCIe 4.0 NVMe SSD, making it a great choice for upgrading a PS5, a laptop, or a desktop computer. It has some of the fastest throughput speeds we have seen in a single consumer-grade PCIe 4.0 SSD.
Specs & Configurations
Bus Type PCI Express 4.0 Capacity (Tested) 2 Controller Maker InnoGrit Interface (Computer Side) M.2 Type-2280 Internal Form Factor M.2 Type-2280 Internal or External Internal NAND Type TLC NVMe Support Rated Maximum Sequential Read 7400 Rated Maximum Sequential Write 6700 Terabytes Written (TBW) Rating 1200 Warranty Length 5 Learn More Acer Predator GM7000 Review -
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![WD Blue SN5100]()
Best Energy-Efficient PCI Express 4.0 M.2 SSDWD Blue SN5100
Pros & Cons
Why We Picked It
Sandisk's WD Blue SN5100, a DRAM-less PCIe 4.0 internal SSD with QLC NAND flash memory, demonstrated strong performance in most of our benchmarks, particularly in our general storage and gaming-centric tests. It comes with a free download of Acronis backup and migration software. It's also designed for energy efficiency (but ships without a heatsink or heat spreader). It's well worth considering if the price is right.
Who It's For
Upgraders with a thermally constrained PC: The SN5100 is designed for energy efficiency, and its DRAM-free architecture and QLC NAND flash memory help keep its price down. It's ideal for upgrading a smaller PC with tight cooling constraints, while maintaining performance; it achieved high scores on both the PCMark 10 Overall general storage benchmark and the gaming-centric 3DMark Storage test.
Mainstream users interested in power savings: The SN5100 prides itself on power efficiency, rated at a maximum 4.1 watts during use. It doesn't require a big heat-dissipation solution; indeed, it doesn't ship with a heatsink or even a heat spreader. It could probably be run barebones in many situations without a significant risk of thermal throttling.
Specs & Configurations
Bus Type PCI Express 4.0 Capacity (Tested) 2 Controller Maker SanDisk Interface (Computer Side) USB-C Internal Form Factor M.2 Type-2280 Internal or External Internal NAND Type QLC NVMe Support Rated Maximum Sequential Read 7100 Rated Maximum Sequential Write 6700 Terabytes Written (TBW) Rating 900 Warranty Length 5 Learn More WD Blue SN5100 Review -
Compare Specs
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Rating |
4.5 Outstanding |
4.5 Outstanding |
5.0 Exemplary |
4.5 Outstanding |
4.5 Outstanding |
3.5 Good |
4.0 Excellent |
4.5 Outstanding |
4.0 Excellent |
4.5 Outstanding |
4.5 Outstanding |
5.0 Exemplary |
Best For | Best PCI Express 3.0 M.2 SSD for Most Users | Best PCI Express 4.0 M.2 SSD for Most Users | Best PCI Express 5.0 M.2 SSD for Most Users | Best Budget PCI Express 4.0 M.2 SSD | Best PCI Express 4.0 M.2 SSD for Sheer Speed | Best PCI Express 4.0 M.2 SSD for Peak Capacity | Best PCI Express 4.0 M.2 SSD for Creative Pros | Best PCI Express 4.0 M.2 SSD for PS5 Upgrades | Best Energy-Efficient PCI Express 4.0 M.2 SSD | Best PCI Express 3.0 M.2 SSD for Most Users | Best PCI Express 4.0 M.2 SSD for Most Users | Best PCI Express 5.0 M.2 SSD for Most Users |
Internal or External | Internal | Internal | Internal | Internal | Internal | Internal | Internal | Internal | Internal | Internal | Internal | Internal |
Internal Form Factor | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 |
Interface (Computer Side) | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 | USB-C | M.2 Type-2280 | M.2 Type-2280 | M.2 Type-2280 |
Capacity (Tested) | 2 | 2 | 2 | 4 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
NAND Type | QLC | TLC | TLC | TLC | TLC | TLC | MLC | TLC | QLC | QLC | TLC | TLC |
Controller Maker | Phison | SanDisk | Silicon Motion | Maxio Technology | Phison | Maxio Technology | Samsung | InnoGrit | SanDisk | Phison | SanDisk | Silicon Motion |
Bus Type | PCI Express 3.0 x4 | PCI Express 4.0 | PCI Express 5.0 | PCI Express 4.0 | PCI Express 4.0 | PCI Express 4.0 | PCI Express 4.0 | PCI Express 4.0 | PCI Express 4.0 | PCI Express 3.0 x4 | PCI Express 4.0 | PCI Express 5.0 |
NVMe Support | ||||||||||||
Rated Maximum Sequential Read | 3500 | 7300 | 14900 | 7400 | 7400 | 7400 | 7450 | 7400 | 7100 | 3500 | 7300 | 14900 |
Rated Maximum Sequential Write | 3000 | 6600 | 14000 | 6500 | 7000 | 7000 | 6900 | 6700 | 6700 | 3000 | 6600 | 14000 |
Terabytes Written (TBW) Rating | 440 | 1200 | 1200 | 3000 | 1200 | 2500 | 600 | 1200 | 900 | 440 | 1200 | 1200 |
Warranty Length | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 5 |
Buying Guide: The Best M.2 SSDs (Solid State Drives) for 2026
The traditional SSD that you can buy and install in a desktop PC, or in place of a spinning hard drive in an older laptop, uses what's known as the "2.5-inch drive" form factor. (In actuality, the drives are about 2.75 inches wide.) These SSDs have the same dimensions as laptop-style hard drives. Years back, SSD makers adopted this standard size to make SSDs compatible with existing laptop designs. (As a result, laptop makers could configure laptops with the choice of a hard drive or an SSD without any retooling.)
Desktop PCs, meanwhile, could accommodate SSDs of this size with little fuss. You can mount them in a 3.5-inch drive bay using a simple bracket, or sometimes even use alternative screw holes spaced for 2.5-inch drives in those same trays or mounting locations. Over time, too, desktop PC chassis have evolved to gain dedicated bays and mounting points for 2.5-inch drives. Indeed, many desktop PC cases now have more 2.5-inch drive mounts than trays for bigger 3.5-inch hard drives.
However, from an engineering perspective, SSDs didn't need to be that large. The enclosure that an SSD comes in has a lot of dead space inside. It's designed in that 2.5-inch size and shape to fit the drive into those existing bays. So when mobile-device designers, challenged with slimming down laptops and tablets, reassessed this issue, the consensus was clear: The bulky 2.5-inch form factor would eventually have to go.
At its core, an SSD is just a thin circuit board studded with flash memory and controller chips. Why not design around that? Thus, the M.2 form factor was born. But we're getting ahead of ourselves.
A Short History of Small SSDs: mSATA to M.2
The first attempt was a new form factor called mini-SATA (mSATA). The boiled-down essence of an SSD with the shell removed, an mSATA drive is a bare, rectangular circuit board. (Most mSATA drives relevant to upgraders measure about 1 by 2 inches.) mSATA drives fit into a dedicated mSATA slot on a laptop's logic board or a PC motherboard. As the name suggests, the slot is a conduit to the Serial ATA bus in the system. The interface on the drive end is an edge connector on the PCB rather than the usual SATA cabling. The mSATA drive also draws all the power it needs through the slot.
(Credit: HP)By relying on SATA, mSATA drives gained all of the advantages and limitations of that interface, including the upper speed limit of SATA 3.0, the latest revision of Serial ATA. That's not a bad thing, mind you. mSATA was also unusual because it piggybacked on an existing connector, known as Mini-PCI, which is often used to install small onboard components, such as compact Wi-Fi cards.
Now, a few mSATA drives still linger on the market, primarily because some older laptop models adopted the form factor years ago, and residual demand exists due to capacity upgrades. However, it's a dead form factor, and mSATA saw only slight adoption on desktop systems.
Even in mSATA's heyday, a replacement was in the works. During development, it was known as NGFF, for "Next-Generation Form Factor." As it took shape, it took on its current, final name: M.2. The drives would be smaller, potentially more capacious, and, most important, not necessarily reliant on the SATA bus.
What Is an M.2 SSD?
M.2 drives are as utilitarian as upgrades come: They look like sticks of gum studded with NAND modules and a controller chip. ("NAND" is the generic term for the flash-memory chips that make up the actual storage on the SSD; the term refers, technically, to the type of logic gates used in the underlying memory structure. See our primer Buying an SSD: 20 Terms You Need to Know for more SSD lingo explained.)
The critical thing to remember about M.2 is that it is a form factor, a shape. The bus—the data pathway the data travels to and from an M.2 drive—is distinct from M.2 itself and can vary. And it can make all the difference in terms of speed and compatibility.
(Credit: Joseph Maldonado)But first, the shape issue. Any M.2 drive you are looking at will be labeled with a four- or five-digit number as part of its specifications or model name. It's actually two measurements, in millimeters. The first two numbers define the drive's width, and the second two or three numbers define the length.
The market has settled on 22mm wide as the standard for desktop and laptop implementations; the aftermarket drives available and the accessible slots we've seen have all been that width. The most common lengths are 80mm ("Type-2280") and 60mm ("Type-2260"). The longer the drive, the more NAND chips you can fit on it (plus, M.2 drives can be single- or double-sided), though note that length isn't an absolute measure of capacity.
Now, why does length matter? Fit, especially when talking about laptops. Most desktop motherboards with M.2 slots have screw-mounting points for several lengths of M.2 drive (usually 80mm, 60mm, and 42mm), so length hasn't been an issue. However, it's a different matter with a laptop that has a user-accessible M.2 slot. The bay may be space-limited to M.2 drives of a specific size, or only to single-sided modules if the thickness tolerances are tight. You'll want to check the available space before shopping.
The latest generation of M.2 drives, using the PCI Express 5.0 bus, also come in the Type-2280 format. M.2 drive length isn't always an indicator of drive capacity, but there are limits to NAND-chip density and how many memory modules engineers can stuff onto a PCB of a given size. As a result, most M.2 drive families we've seen to date have topped out at 2TB or 4TB, though you can find a few 8TB models at lofty prices, and enterprise-class 16TB M.2 modules do exist. The typical capacity waypoints are as follows:
- 120GB or 128GB
- 240GB, 250GB, or 256GB
- 480GB, 500GB, or 512GB
- 960GB or 1TB
- 2TB, 4TB, and 8TB
Smaller-capacity 32GB and 64GB M.2 SSDs are also available for embedded applications or SSD caching, but they are of marginal interest to upgraders or PC builders. Pricing for these drives ranges from 6 to 75 cents per gigabyte, and the most significant factor affecting price is the drive's bus type.
Now, to reiterate an important point: A drive may come in the M.2 form factor, but that says nothing about the bus it uses. Determining that is just as important as making sure it fits.
PCI Express vs. SATA: The Two Main SSD Buses, Explained
This is the trickiest part of an M.2 SSD upgrade. Most of the early M.2 drives were simply ordinary SATA drives stripped down to their fundamentals: a bare circuit board with a different physical connector, but at heart, the same drives as their larger 2.5-inch counterparts. Some of them still are. You won't see better performance with these M.2 SATA drives versus their 2.5-inch SATA equivalents, because ultimately your data is traveling along the same inner pathways inside the computer once it leaves the drive.
That's not a bad thing. Especially with laptops, an older machine might support only M.2 SATA SSDs, and that will be the limit of your upgrade path...end of story. As a result, the only reasons you'd upgrade the drive, in that situation, would be to get more capacity, or if the old one failed.
Nowadays, however, lean, premium laptops can utilize PCI Express-based M.2 SSDs. (All new desktop motherboards with M.2 slots also support PCI Express M.2 SSDs.) These will show a substantial increase in performance in benchmark testing over SATA SSDs, but in most real-world use cases, they'll feel much the same as a fast, premium SATA SSD.
(Credit: Joseph Maldonado)The earliest versions of M.2 PCI Express SSDs used the PCI Express Gen 2.0 x2 interface, which defines a throughput ceiling higher than SATA 3.0's but not enormously so. That evolved into PCI Express Gen 3.0 x2 and x4, paired with a technology called Non-Volatile Memory Express (NVMe) to propel performance even further, especially with heavy, deeply queued workloads.
Beyond that is PCI Express 4.0, a newer version of the PCI Express bus. It has rapidly gained traction and, in most cases, signifies a fast drive. The read and write speeds for some are rated as high as 7,000MBps. These drives are supported on recent desktop systems with recent AMD and Intel chipsets, as well as on the latest mobile platforms. For AMD, that is the X570 and B550 (and later) chipsets (for mainstream Ryzen CPUs) and the AMD TRX40 and later (for Ryzen Threadripper). With Intel, PCI Express 4.0 is supported on Intel 500-series and later chipsets that work with 11th Gen and later desktop CPUs, or on laptops built on 11th Gen and later mobile platforms. You'll want to verify that specific support in the PC's specs, however.
You can use these PCIe 4.0-based SSDs in older AMD- and Intel-chipset systems that support PCI Express 3.0, but they'll run at slower PCIe 3.0 speeds. Fast on PCIe 4.0's heels, though, is PCIe 5.0. Most of the very latest desktop motherboards already support it, but keep in mind that PCIe 5.0 M.2 SSDs are top-end picks. Also, note that just because a motherboard supports the PCIe 5.0 bus doesn't mean the board maker necessarily included a PCIe 5.0-capable M.2 SSD slot. (The 5.0 support may only be extended to ordinary PCIe x16 expansion slots.) Again, check those specs!
What Is NVMe? An SSD Speed Booster
We mentioned NVMe above. NVMe is another technical hurdle to consider, because systems and motherboards need board-level support for these drives to be bootable. All late-model motherboards now support NVMe M.2 drives, but older boards may not support booting from an NVMe drive. Outside of new desktop motherboards, these high-bandwidth, NVMe-capable slots are found in many recent laptops. Also note that in some cases, a laptop may support a PCI Express NVMe drive, but it may be soldered to the motherboard and thus not upgradable. If you're considering upgrading a recent laptop or convertible, consult your manual or online technical documentation closely before purchasing one of these drives.
(Credit: Joseph Maldonado)Among M.2 drives, PCI Express 3.0 and 4.0 x4 M.2 drives that support NVMe are now the norm among aftermarket purchases. These are impressively fast drives, outpacing even the fastest SATA-based SSDs and hard drives. But know that they are more relevant for PC builders or folks upgrading relatively recent systems rather than older PCs, which may not have an M.2 slot, or may have an M.2 slot but not one that supports PCI Express and NVMe—only SATA-based M.2. So, as we said in the previous paragraph, make sure that your system supports this kind of drive before picking one up. You don't want to bring home one of the fastest consumer drives available only to find your system can't use it.
How to Figure Out M.2 Compatibility With Your PC
OK, back from Planet NVMe. Today, the real choice if you're M.2-shopping will be between basic SATA and PCI Express M.2 drives, and for most users, those options will be dictated simply by what your motherboard or laptop can accept. A careful browse of support forums or a call to the vendor's support line should unravel the M.2 bus-compatibility details. On the desktop side of the aisle, some M.2-equipped motherboards support both kinds, although not necessarily on all slots.
If you're looking to upgrade an aged desktop but your PC's motherboard doesn't have an M.2 slot at all, one incidental option is what we call an "M.2 drive on a card" or an AIB SSD (for "add-in-board SSD"). We've seen solutions like this from storage stalwarts such as OWC and Kingston. Additionally, some of Asus' and MSI's high-end motherboards offer an M.2 PCI Express 4.0 "carrier card" to supplement their boards' on-board M.2 slots. These products let you mount an M.2 drive (or drives) on a PCI Express expansion card and tap their speed through the full-size PCI Express slots in a desktop PC that lacks enough M.2 slots. Some such cards support as many as four M.2 drives.
We like these because they often come with a robust heat sink on the M.2 drive(s). Some PCI Express-based M.2 SSDs can run hot during sustained read/write operations and throttle their performance. That said, unless you're running a server or something similar where a drive is constantly subjected to intense read and write activity, you usually don't need to worry about it. That's because many of these drives are so fast, they get their transfer duties done before they can get all that hot.
One last caveat to discuss before our product recommendations surrounds Intel's former SSD line. For a while, Intel sold a family of M.2-based storage products under the brand name Optane in two very distinct types of drives. Intel's "Optane SSDs" were SSDs like any other, bootable drives that can serve as a stand-alone boot drive or as secondary storage. They were discontinued for consumers in 2021, but you may still see the Optane name around. (Intel sold its SSD business at the end of 2021 to SK Hynix, which spun it off into a new subsidiary, Solidigm.)
Intel's "Optane Memory" is a different animal. This is an M.2-format module that looks like an SSD but serves as an accelerating cache for another drive, usually a hard drive. You can read more about Optane Memory in our deep-dive review of the first generation. It's a dead duck now; we only mention it because you may run into it if you upgrade a laptop or desktop from more than a few years ago. If you can, replace the hard drive and the Optane module with a vanilla M.2 SSD if the PC supports it; you'll probably have to reinstall the operating system to make it all work. Better yet, upgrade the whole PC, because it is probably more than five years old.
M.2 Upgrades and Boot Drives: What to Look For
Welcome to the cutting edge! You're shopping for a kind of drive that many folks don't even realize exists. As a result, you need to pay attention to several factors that may not be documented well while you shop. Let's go ahead and recap.
Check the physical size. Be sure the width and, especially, the length (expressed in millimeters) will fit within the available space for the drive. (This is mainly an issue with laptops.) Most will be 22mm wide, but the length varies: 42mm, 60mm, 80mm, and 110mm are the standard sizes, with 80mm being the most common for both standard desktop and laptop upgrades. Many desktop motherboards' M.2 slots can accommodate multiple drive lengths via a mounting post that can be repositioned from hole to hole.
Know which bus you're on. In a laptop upgrade scenario, you're almost certainly swapping out one M.2 drive for another to increase capacity. (Only a few laptops have more than one M.2 slot.) Make sure you know the specifications of the drive coming out of your system—and whether it's reliant on the SATA or PCI Express bus—so you can install the same, presumably roomier kind going in.
For a desktop, it's a bit trickier. Some motherboard M.2 slots support SATA-bus or PCI Express-bus M.2 drives on the same slot. Others support only SATA M.2 drives (those will be older boards), while others support only PCI Express M.2 drives. (And, in the case of PCI Express M.2, not all older motherboards support PCIe x4 or NVMe!) You need to know what your board can use, and buy accordingly. All else being equal, PCI Express should provide a speed boost over a SATA model; nowadays, opt for PCI Express if you have a choice.
(Credit: Joseph Maldonado)Also, look for PCI Express 4.0 or even PCIe 5.0 support with recent drives. If you buy one of those, you'll need a compliant late-model AMD or Intel motherboard to fully leverage their speed. Again, check the specs to avoid overbuying for your system.
Check for bootability. If you're installing an M.2 SSD in a desktop board for the first time, verify with the board maker that an M.2 SSD of the bus type you are considering will be bootable. Though unlikely, a BIOS upgrade may be necessary with an older motherboard. This won't be an issue with boards from recent years.
Compare the cost per gig. Cost per gigabyte is the primary yardstick for pricing-comparing similar M.2 drives from different makers. Expect to pay more for PCI Express bus models, all else being equal, and more for PCIe 4.0 drives than for PCIe 3.0 ones (and more for PCIe 5.0, compared with PCIe 4.0). However, the cost differences are narrowing in both cases. Divide the price (in dollars) by the drive capacity (in gigabytes) to get the cost per gigabyte. For example, a 1TB (1,000GB) drive selling for $99 costs about 10 cents per gigabyte. Use this as a value yardstick for comparing different drives.
(Credit: Joseph Maldonado)Ready to Buy the Right M.2 SSD for You?
We trust that you are now better equipped to make the right choice. Take a look at the spec breakout of the top M.2 solid-state drives that we've reviewed. These are, of course, all internal drives; you can also check out our roundups of the best external SSDs, as well as the best external hard drives for Macs and the overall best external hard drives. Also, if you're also interested in factoring larger 2.5-inch drives into the equation, check out our roundup of the best internal SSDs, which includes some 2.5-inch models.