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Most of today’s newest internal solid-state drives are M.2-format "gumstick" SSDs that run over the PCI Express (PCIe) bus and employ a standard called Non-Volatile Memory Express (NVMe) to maximize data transfer speeds. We've been covering these storage technologies since the get-go, and each year review dozens of SSDs, adhering to rigorous, repeatable performance tests for transfer speeds and program-launch times, and assessing each drive on design, warranty, cost per gigabyte, and more. Below, we've outlined our top tested PCIe NVMe drives for various users and usage cases. We include our favorite PCIe 4.0 and 5.0 SSDs in this roundup, but our best overall basic SSD pick for most users is the Crucial P3, a PCIe 3.0 drive. See that model and the rest below, bolstered by a handy spec comparison and a detailed guide to buying the right high-speed SSD for your desktop or laptop.
Our Top Tested Picks
Crucial P3
WD Black SN850X
Crucial T705
WD Blue SN570
HP FX900 PCIe 4.0 M.2 SSD
SK Hynix Platinum P41
Samsung SSD 990 Pro With Heatsink
Acer Predator GM7000
Lexar NM790
The Best M.2 Solid-State Drive Deals This Week*
- Samsung 990 Pro 2TB M.2 NVMe Gen4 Solid-State Drive — $169.99 (List Price $249.99)
- Crucial P3 1TB M.2 NVMe Gen3 Solid-State Drive — $56.99 (List Price $89.99)
- Samsung 990 Evo 2TB M.2 NVMe Gen5 Solid-State Drive — $129.99 (List Price $239.99)
- WD Black SN850X 2TB M.2 NVMe Gen4 Solid-State Drive — $157.35 (List Price $189.99)
- Crucial T705 2TB M.2 NVMe Gen5 Solid-State Drive — $264.99 (List Price $399.99)
*Deals are selected by our commerce team
Best Overall PCI Express 3.0 NVMe SSD for Most Users
Crucial P3
- Available in capacities up to 4TB
- Low cost per gigabyte for all models
- Includes link for Acronis True Image cloning software
- Good benchmark results for a PCI Express 3.0 drive
- Relatively low write-durability (TBW) ratings
- Lacks 256-bit AES hardware-based encryption
The Crucial P3 is a solid choice as a PCI Express 3.0 NVMe SSD to upgrade your system, providing better-than-hard-drive performance 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 very large amounts of data to the drive. The controller lacks a DRAM cache, which can cause a performance hit for large file transfers. That said, in our testing for everyday tasks, the P3 generally scored well in the PCMark 10 benchmarks.
The Crucial P3 provides on-point 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.
Best Overall PCI Express 4.0 NVMe SSD for Most Users
WD Black SN850X
- Capacities up to 4TB
- Available with or without heatsink
- Exceeded both its sequential read and write speed ratings
- Aced PCMark and 3DMark storage tests
- Lacks 256-bit AES hardware-based encryption
The WD Black SN850X is an upgrade to Western Digital'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 new PC Labs record in the 3DMark Storage benchmark for a PCIe 4.0 SSD). 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.
The WD Black SN850X is a great choice as an elite PCIe 4.0 NVMe M.2 SSD for gaming and/or creative use. It turned in sizzling throughput speeds, and it did well in both our gaming and general storage benchmarks.
Best Overall PCI Express 5.0 NVMe SSD for Most Users
Crucial T705
- Fastest throughput speeds of any SSD we have tested
- AES 256-bit encryption; meets TCG/Opal V2.01 security standard
- Available with an optional heatsink (in two color choices)
- Compatible with Sony PlayStation 5
- Requires a PCIe 5.0-compatible motherboard and CPU to reap its full benefits
- Expensive
With throughput speeds nearly double those of high-performance PCIe 4.0 SSDs, the near-flawless Crucial T705 is the fastest internal solid-state drive (SSD) we've ever tested, delivering currently untouchable transfer rates (assuming you have a PCI Express 5.0-ready desktop to tame the beast). It also set a new PC Labs high score in the PCMark 10 Overall Storage benchmark, which clocks a drive's performance in a variety of everyday tasks, as well as in the 3DMark Storage gaming-centric benchmark. The T705 comes in heatsink and non-heatsink versions, in capacities up to 4TB, and the 2TB stick is also available in a limited-edition white-clad heatsink. The T705 has built-in AES 256-bit hardware-based encryption, the gold standard in drive security.
The T705 is for gamers, creatives, and professionals seeking the ultimate in solid-state drive performance that today only a Gen 5 SSD offers. Just know that being able to run a PCI Express 5.0 SSD at peak speeds can require a considerable additional hardware investment. You must be willing to buy a recent desktop with the hardware to support SSDs built on the PCIe 5.0 standard, upgrade an existing recent rig, or build one from scratch. By making such an investment and having the T705 serve as its brains, though, you're future-proofing your entire setup.
Best Budget PCI Express 3.0 NVMe SSD
WD Blue SN570
- Affordable
- Decent speed for a PCIe 3.0 SSD
- Low write durability rating for a TLC-based drive
- Low AS-SSD program load benchmark score
Despite its name, the WD Blue SN570 is an SSD to drive your budget blues away. The SN570 is a solid performer among affordable PCI Express 3.0 NVMe M.2 SSDs. It is faster than its predecessor, the WD Blue SN550, and delivered above-average results in most of our benchmark tests for a PCIe 3.0 drive. Consider it a solid pick for a terabyte M.2 stick on a budget.
The WD Blue SN570 does well as a budget general-purpose internal SSD for those of us with computers that don't support the PCI Express 4.0 standard. The SN570, the third iteration of Western Digital's popular budget SSD, is faster than ever and proved a solid performer in our benchmark tests. You can have this PCI Express 3.0 NVMe stick for a song—and it won't have you singing the blues.
Best Budget PCI Express 4.0 NVMe SSD
HP FX900 PCIe 4.0 M.2 SSD
- Competitively priced
- Solid benchmark performance, with a few top-tier scores
- Lacks a full heatsink
- Relatively low write-durability (TBW) rating
- No AES 256-bit hardware-based encryption
The HP FX900 isn't the fastest PCI Express 4.0 NVMe SSD on the block, but this M.2 model puts up solid (and, in some cases, excellent) numbers at a surprisingly moderate price. It's a no-frills internal drive that delivered good results even compared with drives that have considerably higher throughput ratings. Among the tests in which it did particularly well are two of significance to gamers: 4K reads and launching Battlefield 5. Its DRAM-less architecture didn't hurt performance for everyday operations (it's more of a factor for very large file transfers), while keeping its cost per gigabyte among the lowest in the PCIe 4.0 SSD segment.
Gamers looking for a budget PCI Express 4.0 stick who realize that there's more to SSD performance than sequential speed ratings will appreciate the HP FX900. It punches above its weight class, holding its own against drives with considerably higher throughput ratings. The FX900 aced several PCMark 10 tests, including ones related to gaming. It's well worth consideration for users looking for a very capable drive at a bargain price.
Best PCI Express 4.0 NVMe SSD for Serious Gamers
SK Hynix Platinum P41
- In our testing, exceeded its sequential speed ratings
- Excellent scores in PCMark 10 and 3DMark benchmarks
- Competitively priced
- Includes drive cloning/migration software
- Supports 256-bit AES hardware-based encryption
- No heatsink included
South Korean memory-chip maker SK Hynix is a relative newcomer to the consumer solid-state drive market, but you would never know that based on its first offerings. The SK Hynix Platinum P41, a PCI Express 4.0 NVMe M.2 SSD, is its best yet. It dominated our PCMark 10 and 3DMark Storage benchmark testing, setting several new records in the process. The P41 supports 256-bit AES hardware-based encryption. SK Hynix provides a clone utility tool, the SK Hynix System Migration Utility, for its SSDs, in addition to Easy Drive Manager software, which lets you see detailed information on drive health, run diagnostics, and erase the drive. And the P41 can be had for a very reasonable price in its 1TB and 2TB capacities.
The SK Hynix Platinum P41 is a worthy choice for anyone looking to buy a high-performance PCI Express 4.0 NVMe SSD without breaking the bank. It blew away several of our benchmark records. The P41 provides AES hardware-based encryption and a clone utility tool as well as SSD management software. Just be forewarned that with its blistering speed, you will want to add a heatsink, the one item of note that it is missing.
Best PCI Express 4.0 NVMe SSD With a Heatsink
Samsung SSD 990 Pro With Heatsink
- Competitively priced
- New high PCMark 10 score for a PCI Express 4.0 SSD
- Works with Sony PlayStation 5
- 256-bit AES hardware-based encryption
- Middling gaming scores compared with other elite PCIe 4.0 SSDs
The Samsung SSD 990 Pro, the company's flagship PCI Express 4.0 NVMe internal solid-state 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. A few other recent internal SSDs have outpaced it in our gaming benchmarks, but its overall capability and deep feature set make this Samsung SSD a versatile drive well-suited for creative tasks.
Though it can't quite match the gaming prowess of some of the latest generation of PCIe 4.0 speedsters, the SSD 990 Pro With Heatsink still offers respectable gaming performance while being a thoroughbred workhorse for creative tasks. It's an appealing choice and a worthy upgrade from the SSD 980 Pro.
Best PCI Express 4.0 NVMe SSD for the PS5
Acer Predator GM7000
- Slightly exceeds its blistering rated speeds
- Good all-around benchmark performance
- 256-bit AES hardware-based encryption
- Includes free cloning-software download
- PlayStation 5 compatible
- Ships with graphene-embedded foam heat spreader rather than aluminum heatsink
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. It tallied some of the fastest throughput speeds we have seen in a single consumer-grade SSD, and performed well in both our general storage and gaming benchmark tests. The Predator offers 256-bit AES encryption, and includes Acronis True Image data cloning and backup software.
The Acer Predator GM7000 is a versatile and feature-rich high-performance PCIe 4.0 NVMe SSD. It showed off its blistering throughput speeds in our testing, and performed well in both our general storage and gaming benchmarks. It can be used with a PS5, a laptop, or a desktop computer. The GM7000 provides AES 256-bit hardware-based encryption, the gold standard in consumer SSD security, and comes with Acronis True Image backup and cloning software. About the only thing it's missing is a full-fledged heatsink, although it does come with a graphene-embedded heat spreader.
Best High-Capacity PCI Express 4.0 NVMe SSD
Lexar NM790
- Competitive pricing for a PCI Express 4.0 SSD
- Available in capacities up to 4TB
- High durability (TBW) rating, especially at smaller capacities
- Strong PCMark 10 Overall and trace performance
- Lacks heat sink
- Does not support hardware-based encryption
The Lexar NM790 internal SSD provides good value in a PCI Express 4.0 NVMe M.2 SSD, keeping costs down by using a DRAM-less architecture. The NM790 has the throughput speeds we expect of a high-performance PCIe 4.0 stick. It aced our Adobe program and Windows launching tests and put up fairly good numbers on our gaming benchmarks. The NM790's durability (TBW) ratings are high, particularly at its smaller 512GB and 1TB capacities. You can get the NM790 in capacities up to 4TB without breaking the bank, making it worth considering for a cost-effective storage upgrade.
The Lexar NM790 is a great pick for frugal shoppers looking for a high-performance PCI Express 4.0 NVMe solid-state drive. It comes in capacities up to 4TB, and unlike many competing SSDs, its cost per gig actually drops when you get to the highest capacity.
PCI Express NVMe Drives 101: How to Buy the Best
Until the last few years, the typical SSD was a little slab, designed to fit into the same space or drive bay inside a PC as a spinning hard drive. You can still find SSDs in this form factor, known as 2.5-inch drives, but times have changed.
Almost all new desktop motherboards and the logic boards of most current laptops incorporate slots meant for much smaller SSDs. These are known as M.2 slots, and they accept SSDs that look like sticks of silicon chewing gum. And depending on the drive, that slim little stick may deliver much faster storage than the bigger drives you're used to.
Why did SSDs take so long to get so small? Actually, from a strict manufacturing viewpoint, they never needed to be that big in the first place. Classic 2.5-inch SSDs have a lot of dead space inside, as memory chips are much smaller than rotating drive mechanisms, but they were designed to fit into existing bays to replace hard drives. In the move from bulky desktops to ultra-slim laptops and tablets, one thing came clear: That fatter kind of drive would have to go. An M.2 drive reduces an SSD to its essentials: just a strip of a circuit board studded with silicon, much leaner and easier to fit into tight spaces.
What Are M.2 Drives? Here's What You Need to Know
Most M.2 drives aren't exactly pretty; they look like bare circuit boards with silicon chips grafted onto them. Some may be topped by a heat spreader or heatsink (usually an array of metal fins) that is equal parts practical and decorative. The most important thing to know about M.2, though, is what it is and what it isn't.
Although M.2 is commonly referred to as an interface, that's not the whole story. M.2 is also a shape or physical form factor, and governs the keying that lets a drive fit onto a motherboard.
The data bus, or pathway, over which your data travels to and from an M.2 drive is a whole other matter, which is where PCI Express and NVMe come in. We'll get to the significance of NVMe in a moment; first, let's discuss the key physical traits of an M.2 drive that you need to understand. (The video below is a good primer.)
As we discuss in our parallel roundup, The Best M.2 Solid-State Drives, M.2 drives are differentiated by a four- or five-digit number listed in their names or specifications. The number is a measurement in millimeters, with the first two digits being the drive's width and the remaining two or three digits telling you how long it is.
In practice, all of today's PC builder- or upgrader-minded M.2 drives and slots are 22mm wide, so you can expect this number to start with 22. The most common lengths are 80mm (M.2 Type-2280) and 60mm (M.2 Type-2260). Drives as short as 30mm (M.2 Type-2230) or as long as 110mm (M.2 Type-22110) do exist, however. Why the differences in length? The longer the drive's PCB (printed circuit board), the more surface area it has to hold memory chips.
Length mostly matters when fitting an M.2 drive into a laptop. Most desktop motherboards with M.2 slots have mounting points for different drive lengths, whereas most laptops fit just one size. Check the space available before you shop.
An M.2 drive's length doesn't always correlate 1:1 with its capacity, but the bigger the stick, the more memory modules engineers can fit onto it. Due to space and density limits, most M.2 drive families top out at 2TB, though 4TB and even 8TB M.2 SSDs exist. You'll see five broad classes of capacity as you shop, with minor variations according to how much data the drive maker has put aside for overprovisioning (a safety margin for when the drive ages and cells start to fail). These capacity classes are:
120GB or 128GB
240GB, 250GB, or 256GB
480GB, 500GB, or 512GB
960GB or 1TB
2TB, 4TB, and 8TB drives
Now let's reiterate an important point: You may know an M.2 solid-state drive's length and capacity, but that doesn't tell you about the bus or interface it makes use of. That detail is vital to know—just as important as making sure the drive physically fits in the space you have.
SSD Bus Technology Basics: PCI Express and NVMe
The first M.2 drives were Serial ATA (SATA) drives, in essence a bare version of their 2.5-inch kin. You can still readily find SATA-bus SSDs in the M.2 form factor, and many M.2 slots will accept them. In some cases, both 2.5-inch and M.2 versions of the same drive are available, with little difference in performance between them. (See our reviews of Samsung's classic SSD 850 EVO 2.5-inch and SSD 850 EVO M.2 from some years back for an illustration.) That's because, with any SATA SSD, your data travels the same path, whether it's a relatively big 2.5-inch drive connected to your PC with a SATA cable or a stick in an M.2 slot.
SATA-based M.2 SSDs are all well and good, but mostly restricted to economy models these days—PCI Express is where the cutting-edge speed is. Your system specifically needs an M.2 slot that supports PCI Express to use these drives; some desktop motherboard slots support both kinds. A given laptop might support only M.2 SSDs that use the SATA bus, which limits what you can do in terms of upgrades. The only reason you'd upgrade in that situation would be to boost the available storage capacity.
Many of today's premium laptops can make use of PCI Express M.2 drives. (Important: Some, like the latest Apple MacBooks, have PCI Express drives soldered, in not-upgradable fashion, to the laptop's mainboard, so "PCI Express SSD" doesn't necessarily imply "removable M.2 SSD module.") As mentioned, almost all new desktop motherboards have M.2 slots, most of which support PCI Express drives.
The first generation of M.2 PCI Express SSDs made use of a PCI Express x2 interface with throughput higher than SATA 3.0, but not enormously so. That's changed. Today's mainstream M.2 drives support PCI Express 3.0 x4 (four lanes of bandwidth), working alongside a technology called Non-Volatile Memory Express (NVMe). The idea behind NVMe is to accelerate performance further, especially with hardy workloads.
NVMe is a control protocol that has come to dominate internal SSDs in recent years. You may have heard of the term AHCI in passing; that's the control scheme used by hard drives and SATA SSDs for data flow over the SATA bus. Though it works with SSDs, AHCI was invented back when hard drives were king. NVMe was designed from the ground up to govern solid-state memory, and is optimized for flash-based storage.
NVMe is the buzzword to look for when buying an M.2 SSD today, but know that your system and its motherboard specifically need to support PCI Express NVMe drives in the BIOS for the drive to act as a bootable device. Most current motherboards support PCI Express x4 NVMe M.2 drives, but you'll want to check on a board-by-board basis. (Some desktop boards have two or more M.2 connectors and support for a given spec can differ from slot to slot.) But outside of desktop motherboards from the last few years, NVMe-compatible M.2 slots are not a given (although you'll find them on almost all new boards). So consult your manuals closely before buying one of these drives.
Also, make sure that if your system supports and you're shopping for an NVMe drive, any PCI Express drive you're considering is specifically an NVMe model. Merely using the PCI Express bus is not necessarily a guarantee of that; PCIe M.2 SSDs existed before NVMe, and though all current models support NVMe, some oldies are still on the market. Today's mainstream solid-state drives are PCI Express 3.0 and 4.0 x4 NVMe M.2 devices, and they leave the fastest SATA-based drives in the dust.
Once again, remember that you need the right motherboard-level support to install one of these drives. For desktops, your motherboard specifications are the place to check. Many recent mobos support both M.2 SATA and M.2 PCI Express/NVMe. For a laptop, you may have to ping the manufacturer's support team to find what's inside (assuming you can even get inside).
Also, as we mentioned, realize that a few laptops solder their SSDs directly to the mainboard to save space, so a drive upgrade may not be possible. Note, too, that upgrading a laptop to a new SSD may violate the terms of any existing warranty.
PCI Express 4.0 vs. 3.0 SSDs: A Solid-State Speed Boost
Ready to shop? Not quite: Increasingly, mainstream drives now cite support for PCI Express 4.0 as opposed to 3.0. We've tested our share of M.2 SSDs that support the upgraded interface, and they are fast indeed. How much you'll be able to tell the difference, though, comes down to what you do with your PC.
Read speeds for some PCIe 4.0 SSDs are rated as high as 7,000MBps. PCI Express 4.0 drives are increasingly mainstream, but you'll need a relatively late-model desktop system to gain their full speed advantages. On the AMD side of things, you need a motherboard employing AMD's X570 or B550 chipset (for mainstream Ryzen CPUs), or a later 600-series chipset, or the AMD TRX40 chipset (for third-generation Ryzen Threadrippers). Intel introduced PCIe 4.0 support with its 11th Generation "Rocket Lake-S" desktop processors and its Intel Z590 chipset platform and brought it to the laptop market with its 11th Gen "Tiger Lake" mobile CPUs. Breaking it down to simple advice: Check your system or motherboard's specs for specific M.2 PCI Express 4.0 support, as there always exceptions, too. You'll likely only see it if your PC is less than a couple of years old.
You can use these PCIe 4.0-based SSDs in PCIe 3.0-only systems, but they'll just dial down to PCIe 3.0 speeds. So should you opt for one? If you'll be assembling or upgrading a late-model AMD or Intel PC with the right chipset, by all means. Hard-core gamers and content creators working on today's newer PCs will stand to gain the most. If you have a PCIe 4.0-capable slot for one, get one; otherwise, 3.0 will likely do you fine.
PCI Express 5.0: Leading-Edge SSD Speed
The current ultimate picks in internal storage are PCI Express 5.0 (aka Gen 5) NVMe SSDs, which support blistering throughput speeds (up to about twice as fast as PCIe 4.0 SSDs at peak throughput). Many of the major SSD manufacturers have rolled out—or at least announced—their first PCIe 5.0 models in 2023. But the hardware requirements are very specific, and recent: To run one of these at its intended peak speed, you'll need to buy a new Gen 5-compatible desktop PC, build a system from scratch, or update your rig's motherboard and CPU to a very late-model pair.
Specifically, Intel users will need a 12th Gen or later Core CPU with a motherboard based on Intel's Z690 or Z790 chipset. AMD fans must have a Ryzen 7000 series processor or later, and an AM5 motherboard with an X670, X670E, or B650E chipset. Important: You'll also have to be sure the motherboard actually has a PCI Express 5.0 M.2 slot implemented. The chipset is not a guarantee of that, just an indication that the motherboard maker could include one. (Some of these boards will have only PCI Express 5.0 x16 expansion card slots, and not 5.0-compliant M.2 SSD slots. It's easy to misread that on a spec sheet, so be wary.)
With all that in place, Gen 5 SSDs, equipped with either their own heatsink or the one supplied with the motherboard, are capable of phenomenal throughput speeds, up to a theoretical maximum of 14,000MBps read and write. This does not necessarily translate into increased speeds at all tasks; the PCIe 5.0 SSDs we have reviewed have done particularly well at gaming and file-copying tasks. Yes, PCI Express 5.0 drives are wicked fast, but you will likely end up having to build or buy a whole PC to support one.
NVMe in Other Shapes: PCI Express Expansion Cards and U.2 Drives
If you're looking to add a PCI Express/NVMe drive to a desktop with an older motherboard that lacks M.2 slots, one option is an M.2 drive on a "carrier card." In essence, an M.2 drive gets fitted onto a PCI Express expansion card that drops into a desktop PCIe slot of at least four lanes.
We've seen solutions like this from Asus, Gigabyte, Kingston, and others. Also, a few motherboard makers bundle an empty M.2 carrier card in the box with their high-end mainboards. With one of these, an M.2 drive on a PCIe expansion card lets you tap the speed of PCI Express/NVMe without having a supporting M.2 slot. With older motherboards, the card may also add bootability, so check for that.
Some PCI Express M.2 SSDs can run hot under sustained use, so having the M.2 module mounted on a vertical card can also mean better ventilation, and in theory less throttling due to heat. That said, these drives are so fast that under most normal use they finish data transfers before heat can become a major issue.
One other form that NVMe drives take, the U.2 drive, is confined at the moment to just a handful of SSDs. Its physical interface is much more common in servers than in consumer PCs. A few high-end motherboards may have onboard U.2 ports, but most will require a specialized U.2 adapter that plugs into an M.2 slot.
NVMe Drives: Shopping Tips
MEASURE TWICE, BUY ONCE: SIZE IS KEY. We've explained the secret code to decipher the length and width of an M.2 drive. Make sure the drive's length matches the available space, especially with laptop upgrades. Most aftermarket drives will be 60mm or 80mm long. Also check any heatsink or spreader atop the drive and make sure it won't interfere vertically with installation. (You can often remove a heatsink, but if it's there, it's usually for a good reason.) For the most part, an M.2 SSD wearing a thick heatsink is unsuitable for laptop use.
PAY ATTENTION TO THE BUS DETAILS. With laptops, an SSD upgrade is often a binary choice that hinges on the kind of drive supported—SATA or PCI Express, end of story. The usual scenario is that you're swapping out one M.2 drive for another of the same bus type and overall specs, but with a larger capacity. Most laptops don't have spare or empty M.2 slots, so your decision path is pretty straightforward.
Desktop motherboards are more complicated, in that some M.2 slots support both SATA and PCIe drives. In boards with two or more M.2 slots, this may vary between slots. Some support only SATA; others only PCI Express; and an older motherboard may support only PCI Express x2 instead of x4. In short, it's a swamp to be navigated with care. You need to know exactly what your board is optimized to use and buy accordingly. Check the motherboard's spec sheet.
CHECK FOR BOOTABILITY. If your desktop is getting a PCI Express/NVMe drive for the first time, verify with the motherboard or PC maker that the drive will be bootable. It's unlikely, but a BIOS upgrade may be required to get you there. (This is an issue with older motherboards, not current ones.)
PRICE IT OUT PROPERLY. Comparing SSDs in terms of value for money is tricky, but the best metric is price per gigabyte. PCIe drives tend to command a premium over SATA SSDs. Divide the price (in dollars) by the capacity (in gigabytes) to get the cost per gig; for instance, a 1TB drive that sells for $100 works out to about 10 cents per gigabyte. That's a ruler you can use to compare drives of different capacities.
Ready to Buy the Right PCI Express SSD for Your PC?
Not finding any SSDs in this list that look right for you? Check out the full feed of our latest SSD coverage. Also see our roundup of the best M.2 solid-state drives for more about M.2 drives in general. And if you're also considering a 2.5-inch SATA drive, check out our guide to the best internal SSDs overall, which evaluates M.2 and SATA drives together.
For more storage options, also refer to our roundups of the best budget SSDs, as well as the best external hard drives for PCs and for Macs.