The Best SSDs for Upgrading Your Laptop in 2026

One of the most effective ways to improve an aging laptop is to install a new solid-state drive (SSD). Choose the right one, and you can supercharge your computer's storage capacity and its performance. How to find the one for your needs? That's where we come in. We've been testing storage devices since the dawn of the PC more than four decades ago using rigorous, repeatable benchmarks. We analyze and review the performance, specs, features, strengths, and weaknesses of each drive we recommend. Our current top pick for most laptop upgrades is the Sandisk Optimus 5100 (aka the WD Blue SN5100), a PCI Express 4.0 drive. We've laid out the strengths of that and a host of other top laptop-friendly SSDs we have tested and chosen for specific upgrade scenarios. Read on to see them all, plus detailed guides and spec breakouts that illustrate how to choose the right drive for your specific laptop.

Best M.2 SSD for Laptop Upgrades (PCI Express 4.0)

WD Blue SN5100

Score: 4.0

Pros & Cons

• + Exceeded its Crystal DiskMark sequential read and write speed ratings

• + Excellent 4K read benchmark results

• + Above-par PCMark 10 Overall and 3DMark 10 scores

• + Energy-efficient architecture

• + Includes downloads for Acronis True Image and Sandisk Dashboard software

• - Exceeded its Crystal DiskMark sequential read and write speed ratings

• - Excellent 4K read benchmark results

• - Above-par PCMark 10 Overall and 3DMark 10 scores

• - Energy-efficient architecture

• - Includes downloads for Acronis True Image and Sandisk Dashboard software

Why We Picked It

Sandisk's Optimus 5100—a DRAM-less PCI Express 4.0 internal SSD with QLC NAND flash memory—has a lot of strong points for mainstream upgraders of recent-vintage laptops. It performed well in our testing, especially in our general-storage and gaming-centric benchmarks, and also comes with a free download of Acronis backup and migration software. It is well worth considering if you can find it at a good price, though that's a tough proposition amid the RAM shortage.

Note: This drive is now sold under Sandisk's new Optimus branding at some retailers, though you may still find it listed under its former name, WD Blue SN5100 (which is what it used when we reviewed it).

Who It's For

People with basic computing needs:Because it lacks a heat sink, the 5100 isn't a good choice for reading and writing very large files frequently. If you mostly use your laptop to browse the internet or do productivity work, though, it'll do just fine.

People who need to set up laptop backups:The drive comes with a download for Acronis True Image backup and migration software, as well as one for the Sandisk Dashboard utility.

Specs & Configurations

Internal or External: Internal

Internal Form Factor: M.2 Type-2280

Interface (Computer Side): M.2 Type-2280

Capacity (Tested): 2 TB

NAND Type: QLC

Controller Maker: SanDisk

Bus Type: PCI Express 4.0

NVMe Support: True

Rated Maximum Sequential Read: 7100 MBps

Rated Maximum Sequential Write: 6700 MBps

Terabytes Written (TBW) Rating: 900 TBW

Warranty Length: 5 years

Best Budget M.2 SSD for Laptop Upgrades (PCI Express 4.0)

Samsung SSD 990 EVO

Score: 4.0

Pros & Cons

• + Supports AES 256-bit full-disk hardware encryption

• + TCG/Opal V2.0 security compliant

• + Heat-spreader label minimizes throttling

• + Five-year warranty

• - Supports AES 256-bit full-disk hardware encryption

• - TCG/Opal V2.0 security compliant

• - Heat-spreader label minimizes throttling

• - Five-year warranty

Why We Picked It

The Samsung SSD 990 EVO does well as a mainstream internal SSD for general home and business storage use. This DRAM-less SSD is moderately priced and energy-efficient, offers advanced security features, and includes the Samsung Magician suite of SSD-optimization tools. It's a PCI Express (PCIe) 4.0 M.2 drive, and while Samsung notes that the SSD 990 EVO can run in a PCIe 5.0 slot, it can use only two of that interface's four lanes. A better role for it is as a workaday PCIe 4.0 stick.

Who It's For

Home users:The Samsung SSD 990 EVO proved a capable performer among mainstream PCIe 4.0 internal SSDs in our testing, with generally excellent scores in our PCMark 10 benchmarking, which measures an SSD's speed in performing a range of common storage tasks. It has the warranty, software, and security features that we have come to expect from Samsung's SSDs. The drive's DRAM-less architecture keeps its price down, the heat spreader keeps it cool, and it is very energy-efficient.

General business users:The SSD 990 EVO lacks the speed and performance for high-impact tasks such as video production that we see in elite PCI Express 4.0 SSDs. But its on-point PCMark 10 scores for a drive in its speed class make it well-suited for general office use. Its support for AES 256-bit full-disk hardware encryption can keep your data safe from brute-force attacks, too.

Specs & Configurations

Internal or External: Internal

Internal Form Factor: M.2 Type-2280

Interface (Computer Side): M.2 Type-2280

Capacity (Tested): 2 TB

NAND Type: TLC

Controller Maker: Samsung

Bus Type: PCI Express 4.0

NVMe Support: True

Rated Maximum Sequential Read: 5000 MBps

Rated Maximum Sequential Write: 4200 MBps

Terabytes Written (TBW) Rating: 1200 TBW

Warranty Length: 5 years

Best M.2 SSD for Laptop Upgrades (PCI Express 3.0)

Crucial P3

Score: 4.5

Pros & Cons

• + 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

• - 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

Why We Picked It

The Crucial P3 is a solid choice as a basic PCI Express 3.0 SSD to upgrade your system, delivering good performance at a relatively modest price. Its QLC flash memory helps enable higher capacity (up to 4TB) and keeps its cost per gigabyte down relative to SSDs with TLC flash; 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 can cause a performance hit on some SSDs, especially during large file transfers, but the P3 generally scored well in the PCMark 10 benchmarks for everyday use.

Note that Crucial's parent company, Micron, is exiting the consumer/retail SSD business (it continues to make drives for system makers and data centers) and is winding down the Crucial brand. Micron will continue to support its Crucial drives through the end of their warranty period, but know that Crucial SSDs will begin to fade from the market soon.

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 relatively low 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 in a difficult market for users who don't need the latest SSD speeds, thanks to its PCIe 3.0 interface and QLC NAND flash memory. Though it won't set any speed records, it performed well for a PCIe 3.0 stick in our benchmarks.

Specs & Configurations

Internal or External: Internal

Internal Form Factor: M.2 Type-2280

Interface (Computer Side): M.2 Type-2280

Capacity (Tested): 2 TB

NAND Type: QLC

Controller Maker: Phison

Bus Type: PCI Express 3.0 x4

NVMe Support: True

Rated Maximum Sequential Read: 3500 MBps

Rated Maximum Sequential Write: 3000 MBps

Terabytes Written (TBW) Rating: 440 TBW

Warranty Length: 5 years

Best M.2 SSD for Laptop Upgrades (PCI Express 5.0)

WD Black SN8100

Score: 5.0

Pros & Cons

• + Available in capacities up to 8TB

• + Screaming-fast random read/write speeds

• + Exceptional PCMark 10 benchmark performance

• + Includes Acronis True Image backup and migration software

• + Meets TCG/Opal V2.0 security standard

• - Available in capacities up to 8TB

• - Screaming-fast random read/write speeds

• - Exceptional PCMark 10 benchmark performance

• - Includes Acronis True Image backup and migration software

• - Meets TCG/Opal V2.0 security standard

Why We Picked It

The Sandisk Optimus GX Pro 8100 is the current champ of internal SSD speeds, ruling in our benchmark testing while generating surprisingly little heat for a PCI Express 5.0 M.2 SSD. The 8100's exceptional overall performance, power efficiency, software, and security make it an exceptional high-performance internal SSD. The 8100 is now sold under the Sandisk Optimus brand, though you may still see it listed under its old name (WD Black SN8100, which is also what it was called when we reviewed it) at some retailers.

Who It's For

People with exceptionally powerful and well-cooled laptops:The 8100 is only a good fit for very high-end laptops that need a capacity boost or have a second PCIe 5.0-capable M.2 slot. Most other laptop upgraders would be fine with a PCIe 4.0 SSD.

Gamers and power users:PCIe 5.0 is the cutting edge of consumer-grade SSD performance. It mostly appeals to creative pros, gamers, power users, and DIY-ers, and products like the 8100 help it thrive within these markets.

Specs & Configurations

Internal or External: Internal

Internal Form Factor: M.2 Type-2280

Interface (Computer Side): M.2 Type-2280

Capacity (Tested): 2 TB

NAND Type: TLC

Controller Maker: Silicon Motion

Bus Type: PCI Express 5.0

NVMe Support: True

Rated Maximum Sequential Read: 14900 MBps

Rated Maximum Sequential Write: 14000 MBps

Terabytes Written (TBW) Rating: 1200 TBW

Warranty Length: 5 years

Best M.2 SSD for Upgrading a Gaming Laptop

WD Black SN850X

Score: 4.5

Pros & Cons

• + Available in capacities up to 8TB, with or without a heatsink

• + Exceeded both its sequential read and write speed ratings

• + Aced PCMark and 3DMark storage tests

• - Available in capacities up to 8TB, with or without a heatsink

• - Exceeded both its sequential read and write speed ratings

• - Aced PCMark and 3DMark storage tests

Why We Picked It

The Sandisk Optimus GX Pro 850X is an upgrade to Sandisk's high-performance PCI Express 4.0 NVMe internal gaming SSD, the WD SN850. The 850X improves on an already excellent drive by offering an 8TB option and an upgrade in flash memory technology that boosts sequential read and write speeds. It turned in beefier 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.

Note that Western Digital has spun off its SSD business  as a separate company, Sandisk, which has rebranded WD's Blue and Black SSDs as its Sandisk Optimus SSD family . The old name for this drive is WD Black SN850X, and you may still see some retailers selling it under this name.

Who It's For

Upgraders seeking a blend of speed and capacity:The 850X proved 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. Also, now that it's available in capacities up to 8TB, the 850X can host a large media or game library.

Gamers:The 850X delivers real gaming prowess for a PCIe 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. Plus, its larger 4TB and 8TB models (we tested the 2TB) let you store a massive gaming library with room to spare.

Specs & Configurations

Internal or External: Internal

Internal Form Factor: M.2 Type-2280

Interface (Computer Side): M.2 Type-2280

Capacity (Tested): 2 TB

NAND Type: TLC

Controller Maker: SanDisk

Bus Type: PCI Express 4.0

NVMe Support: True

Rated Maximum Sequential Read: 7300 MBps

Rated Maximum Sequential Write: 6600 MBps

Terabytes Written (TBW) Rating: 1200 TBW

Warranty Length: 5 years

Best SATA SSD for Everyday Laptop Upgrades

Samsung SSD 870 EVO

Score: 4.5

Pros & Cons

• + Record-setting 4K results for SATA drives

• + Strong write-durability rating

• + Samsung Magician is the gold standard of SSD management software

• - Record-setting 4K results for SATA drives

• - Strong write-durability rating

• - Samsung Magician is the gold standard of SSD management software

Why We Picked It

SATA drives still have their place in the SSD world, as the primary storage in legacy systems and as supplementary storage in M.2 systems; they're much faster than spinning hard drives. The Samsung SSD 870 EVO, our favorite SATA SSD, comes in capacities up to a whopping 8TB. In the PCMark 10 Overall benchmark, which measures overall storage performance, it outperformed some lower-end M.2 SSDs.

Note that since late 2025, due to a worldwide memory shortage, SSD prices have risen dramatically. SATA drives have been hit, too. Some remain relative bargains, but among our best-rated SATA SSDs, including the SSD 870 EVO, their cost per gigabyte may exceed that of many M.2 drives. Still, prices fluctuate considerably. In the meantime, you have several choices: Hold off on upgrading that SATA drive for now, bite the bullet and go with the best, or retire that SATA-based computer and replace it with another laptop or a budget desktop .

Who It's For

Upgraders of old laptops:If you want to replace or upgrade the SSD in a legacy SATA-based computer, the Samsung SSD 870 EVO is the best we have encountered. It did particularly well in the PCMark 10 Overall general-storage benchmark, in tasks like booting Windows, loading game levels, and launching creative programs like those in Adobe's creative suite.

Capacity seekers:The SSD 870 EVO's peak capacity of 8TB ties for the largest capacity among consumer SATA drives you can buy. If you can't install it in your laptop, another option is to put the 870 EVO in an inexpensive SATA drive enclosure, effectively turning it into an external drive that you can connect via a USB cable to your computer.

Specs & Configurations

Internal or External: Internal

Internal Form Factor: 2.5-Inch

Interface (Computer Side): SATA

Capacity (Tested): 4 TB

NAND Type: TLC

Controller Maker: Samsung

Bus Type: Serial ATA

NVMe Support: False

Rated Maximum Sequential Read: 560 MBps

Rated Maximum Sequential Write: 530 MBps

Terabytes Written (TBW) Rating: 2400 TBW

Warranty Length: 5 years

Best SATA SSD for Peak Capacity in a Laptop Upgrade

Samsung SSD 870 QVO

Score: 4.0

Pros & Cons

• + Excellent price-to-performance ratio for a SATA-based SSD

• + Very fast 4K read and write speeds

• + Feature-rich Magician management software

• + 8TB version coming soon

• - Excellent price-to-performance ratio for a SATA-based SSD

• - Very fast 4K read and write speeds

• - Feature-rich Magician management software

• - 8TB version coming soon

Why We Picked It

Although no SATA SSD can approach the raw sequential throughput of even a PCI Express 3.0 SSD, the Samsung SSD 870 QVO, a 2.5-inch SATA 3.0 SSD, had no trouble keeping up with its NVMe cousins in  some  key areas during our review. Its QLC NAND helped keep its cost per gigabyte down while permitting higher capacities—it was among the first SATA drives to have an 8TB version.

Today, we are in a far less favorable market for consumers due to a worldwide memory storage—SSD prices, including for SATA drives, have skyrocketed, with no end in sight. Other 8TB SATA drives are on the market, but in terms of cost per gigabyte, the 870 QVO is still a relative bargain among our top-rated models. It still carries a hefty price tag in its highest capacity, but it's less costly than the 8TB model of our all-around SATA SSD favorite, the Samsung SSD 870 EVO.

Who It's For

Users seeking maximum capacity and value:If you have the cash and you're set on expanding the capacity of your legacy SATA computer, the 8TB SSD 870 QVO represents a good value pick on a cost-per-gigabyte basis. It was a solid performer on our benchmarks when we tested it, turning in fast 4K read and write speeds even compared with some M.2 drives.

Everyday SATA upgraders:The SSD 870 QVO comes in at a relatively low cost per gigabyte among our top-rated SATA drives, and turned in good benchmark scores for its price. Plus, the Samsung Magician software suite, which supports 256-bit AES hardware-based drive encryption, is a worthy differentiator.

Specs & Configurations

Internal or External: Internal

Internal Form Factor: 2.5-Inch

Interface (Computer Side): SATA

Capacity (Tested): 2 TB

NAND Type: QLC

Controller Maker: Samsung

Bus Type: Serial ATA

NVMe Support: False

Rated Maximum Sequential Read: 560 MBps

Rated Maximum Sequential Write: 530 MBps

Terabytes Written (TBW) Rating: 720 TBW

Warranty Length: 3 years

The Basics: Understanding Laptop SSD Upgrades

"SSDs: OK, where can I get one?" might be your first question. First, you'll need to do some homework to see whether your laptop can support an SSD upgrade. Really, really old models might not have BIOS support for SSDs at all, but a laptop that old probably isn't worth upgrading to start with. What you need to know is the kind of drive in the laptop now and whether you can get to it easily for a swap.

Be aware, though: Laptops vary wildly in how easy or hard it is to access the main hard drive. Some mainstream machines will provide access to the hard drive through a bottom hatch (uncommon), a slide-out bay along the edge (very uncommon), or, failing that, by removing the entire bottom panel or the keyboard (most common). So, to get started, flip your laptop over and check for a hatch on the underside, secured with a small screw or two. If the hatch says "HDD" or something similar, so much the better. But don't count on finding one.

Alas, the trend with many manufacturers in recent years has been to make it either difficult or impossible to access the parts inside the laptop on your own. The chassis might use proprietary or uncommon screws that you'll need special tools to remove, or the underside might be sealed in such a way that the only way inside is with a specialized process or tool that only the manufacturer's repair team is privy to.

The best places to get the skinny on drive access, if you can't find an obvious access hatch yourself from the laptop's outside, are the laptop maker's tech-support site, online forums, YouTube, and documents maintained online by the maker. Doing your homework before buying—or doing anything else, for that matter, such as prying—is key. Don't disassemble the laptop's bits at random.

In this same vein, there's another recent issue with laptop-storage upgrades: As more and more machines move toward thin, light profiles, so have the drives themselves. To accommodate demand for thinner machines, manufacturers have abandoned 2.5-inch SSDs, which are the same size as the hard drives that once dominated laptop interiors. Instead, you may find that you have an M.2 solid-state drive , which is a tiny sliver of a drive shaped like a stick of gum. On most M.2-equipped laptops from the last five years or so, an M.2 drive will use the PCI Express bus and employ a speed-up technique called NVMe; older M.2 machines might use the conventional Serial ATA (SATA) bus with an M.2 drive. While M.2 drives are great as space conservers, it can be trickier to figure out how to replace them. Also, in some increasingly common cases, the laptop will have neither a 2.5-inch drive nor an M.2 drive: The SSD will be soldered to the motherboard itself. In that case, sorry, no internal upgrade for you! (Consolation: Check out our guide to the best external SSDs .)

Again, we should stress that nowadays, even  looking  in the direction of your laptop with a screwdriver in our hand might mean voiding your warranty. So make sure you read the details of your warranty coverage, if it's still in force, before undertaking this process.

How Much Does a Laptop SSD Upgrade Cost?

We're in the midst of a RAM and flash-memory shortage with no end in sight, so you may have to pay a pretty penny for a new SSD to upgrade your laptop. A high-quality 1TB M.2 drive now costs around $200, with 2TB M.2 models averaging around $350 and 4TB M.2 drives retailing at $600 and up. (SATA 2.5-inch drives tend to be cheaper at each of those capacities, if you can use one.) So while this type of upgrade is certain to boost performance, it's far from a bargain versus pricing a year or two ago.

If you're also upgrading your laptop's memory, that will make a huge dent in your wallet, too. For tips on how to save money, check out our complete guide to navigating the memory shortage. It's geared toward people building desktop PCs, but much of it applies to laptop upgrades, too.

How to Identify the Kind of SSD Your Laptop Needs

For an upgrade to be worthwhile, you'll be moving (1) from a platter-based, 2.5-inch SATA hard drive to a 2.5-inch SATA SSD, (2) from a 2.5-inch SATA hard drive to a higher-capacity SATA hard drive (or a roomier 2.5-inch SSD), or (3) from a cramped SSD of any kind to a roomier one of the same kind.

If the laptop has a hard drive that needs to be upgraded, it will be a 2.5-inch "laptop-style" hard drive with a Serial ATA (SATA) interface. (To learn more about all the terms you need to know in the world of mobile storage,  check out our SSD dejargonizer .) This kind of drive is easy to swap out for a 2.5-inch SATA-based SSD, assuming you can access the drive. Some of the relevant SSDs available to consumers are 2.5-inch drives, with the SSD enclosed in a shell the size and shape of a laptop hard drive. There is also the possibility that the laptop already has an SSD inside in the 2.5-inch drive form factor, the same size and shape as a platter drive. You can simply swap that out for another, roomier one.

Another possibility, especially in a thin, late-model laptop: It may already have an SSD inside in one of two alternative form factors: mSATA or M.2. These days, manufacturers use only M.2 in new laptops; some laptop models from years back used the now-defunct mSATA. Both, though, implement the SSD as a wafer-thin, bare circuit board. (To tell them apart: Most mSATA SSDs measure 31mm wide by 50mm long; M.2 drives are skinnier, at 22mm wide.) They can save a lot of space inside a laptop, but obviously, you can't swap in a much bigger 2.5-inch drive in their place.

An mSATA SSD can only be swapped for another mSATA SSD, but the mere presence of mSATA signals an old laptop. If you have an M.2 boot drive, it's usually only worthwhile upgrading it if you are installing a larger-capacity SSD. (See our roundup of the  best M.2 solid-state drives  for more on M.2 and the perplexing variety of these drives.) Bear in mind that M.2 gumstick-style SSDs all look similar, but they can use either PCI Express or SATA as their bus interface. Your laptop likely supports only one bus type in the M.2 slot, so make sure you know which you need and what you're getting.

Note that it's uncommon, but some large-chassis, recent-vintage workstation laptops for power users and big gaming laptops can have more than one M.2 slot. You may be able to add a second or third M.2 SSD rather than just swapping out the boot drive. That's why checking with the laptop maker matters.

Most older laptops with an accessible PCI Express M.2 slot use PCI Express (aka PCIe) 3.0. Mainstream models from the last few years use M.2 SSDs that support the more recent, faster PCIe 4.0; laptop makers have largely adopted PCIe 4.0 drives in newer models. PCI Express 4.0 drives tend to be fast and generate a bit of heat, but an M.2 stick with a hulking heatsink won't fit in a laptop's M.2 slot; one with a thin graphene heat spreader might. Granted, most laptops with a PCIe 4.0-capable M.2 slot will likely come with a compatible SSD already in place. (If you put a PCIe 4.0 drive in a PCIe 3.0 slot, it will work, but it will default to PCI Express 3.0 speeds.)

As for the very latest speed flavor of SSDs, PCI Express 5.0, generally the word is fuhgeddaboutit. Yes, you could run one in an M.2 slot on any recent laptop, but it would revert to PCIe 3.0 or 4.0 speeds, defeating the purpose of investing in it. That said, an elite tier of recent high-end laptops do offer a PCIe 5.0 M.2 slot or two, and a small but growing number of PCI Express 5.0 sticks with power-conservation and heat-dissipation features can run in these slots. Although these SSDs tally PCIe 5.0 throughput speeds, it remains to be seen whether they offer much performance benefit in laptops for everyday storage tasks, the graphic arts, or gaming versus the best PCIe 4.0 SSDs we have tested. They're just not that widely implemented yet.

M.2 SSDs also come in different lengths, so you don't want to buy one that's too long for the available space. (A shorter one might work, depending on the design.) Most M.2 drives come in what's known as the Type-2280 form factor, which indicates the drive's width and length: 22mm wide and 80mm long. A Type-2242 (42mm) or Type-2260 (60mm) drive might be used by a laptop maker for space savings. You can use a shorter SSD than the current one if the laptop's mainboard has screw-mounting points to fasten it onto; it may well not.

M.2 drives also come in slightly varying thicknesses (which is down to whether the design has a single side covered with chips, versus both sides) that will, more often than not, correspond to their available storage size. The more storage cells an M.2 drive needs, the more likely it is to be double-sided. Again, you need to know what type of drive you have before you buy, so we recommend looking in the manual, checking any available datasheets, or contacting support as a first resort.

SSD Drive-Height Considerations: Through Thick or Thin

Let's talk about 2.5-inch SATA drives for older laptops. Almost all recent-model 2.5-inch SATA SSDs are 7mm thick, but in years past, 9.5mm-thick drives were a thing. Those measurements were not arbitrary: Older 2.5-inch hard drives meant for laptops tended to be 9.5mm thick, so early SATA SSDs' outer cases were sized to fill those bays, but both kinds eventually slimmed down to 7mm. Now, drive bays in the few new laptops that still support SATA accommodate only the 7mm size, so thinner SSDs are necessary.

A 2.5-inch drive bay inside the laptop will be engineered to accept only one of those thicknesses. If it's a 9.5mm-high bay, most current SSDs will have a little bit of wiggle room in the bay. That's not a bad thing, but not ideal; you want the SSD to fit snugly, so wobble inside the bay doesn't stress the SATA connector (and you don't hear any unnerving rattling). You should check whether the SSD vendor bundles a plastic spacer to keep the drive seated firmly in the bay, if you need one. Few if any SSD makers do anymore, though. You could always improvise one from non-conductive (please!) scrap materials or find an aftermarket one; a ready-made one will fit better and feel more professional.

If the 2.5-inch bay is 7mm high, then it will fit most modern SATA 2.5-inch SSDs snugly.

Know Your SSD Software

Some drives will come with a license for a drive-copy or "ghosting" app such as Acronis TrueImage. This is a nice premium, but we don't consider the presence or absence of such software a deal-breaker, as we've had good luck performing the tasks involved (such as drive cloning) with free software like  EaseUS Disk Copy Home .

That said, some makers are better than others at drive-specific utility software. Some SSDs come with none; others, such as Samsung's SSD EVO and Pro drives, come with sophisticated tweaking and monitoring apps, epitomized by Samsung's Magician app.

Ready to Buy the Right SSD for Your Laptop?

Our top picks include SSDs for every type of laptop that's upgradable, but there's also the question of whether all this trouble is actually worth it. (For example: A laptop old enough to support only 2.5-inch drives, these days, is a laptop that's probably getting old enough to be replaced for other reasons.) If you simply want to add more storage to your laptop, and the prospects of getting inside the chassis are bleak (or the SSD is soldered down), check out our roundups of the  best external SSDs , as well as the  best external hard drives for Mac and the  best external hard drives  overall. If you just want a place to keep more photos, music, or files that you don't access all that often, one of these external solutions might suffice, with no screwdriver or OS transfer required.

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