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 of the M.2 drives we've seen to date have topped out at 2TB, though you can find a few 4TB and 8TB models at lofty prices. The typical capacity waypoints are as follows: Know which bus you're on. In a laptop-upgrade scenario, you're almost certainly swapping out one M.2 drive for another, with the intent of gaining capacity. 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. An external NVMe SSD is excellent if you can utilize its speed to improve your workflow, but these SSDs fall behind what SATA SSDs can offer when it comes to price and endurance. The Oyen Digital U32 Shadow is an example of a well-built SATA SSD that is a great storage medium for those who need a fast and reliable way to transfer their data between devices.

The drive utilizes the Phison E12S PCIe 3.0 controller. Although newer drives with PCIe 4.0 arrive with the newer Phison E16 and E18 controllers. But unless these SSDs use TLC, the QLC flash will still be a limiting factor in speed. 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 very well while you shop. Let's recap. The largest consumer SSDs we have to compare against are Samsung's earlier 4TB SATA SSDs. We've included the 4TB 860 EVO. For some tests, we also have included results from a few enterprise drives: 8TB NVMe models from Intel and SK hynix, and 4TB SATA drives from Kingston and Samsung. These all use TLC NAND, but without SLC caching. However, from an engineering point of view, SSDs didn't needto be that big. The enclosure an SSD comes in has a lot of dead space inside. It's designed in that 2.5-inch size and shape to make the drive fit 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, eventually, would have to go. 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 980 Pro's Editors' Choice award, because other recent internal SSDs have outpaced it in our gaming benchmarks, but its overall capability makes this Samsung a versatile drive well-suited for creative tasks. Who It's For

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Nowadays, though, many lean, premium laptops can make use of PCI Express-bus M.2 SSDs. (Just about all new desktop motherboards with M.2 slots also support PCI Express M.2 SSDs, too.) With these, you may see a substantive increase in performance in benchmark testing, but in most real-world usage, they'll just feel like a fast, premium SATA SSD. (Credit: Molly Flores) The earliest versions of M.2 PCI Express SSDs made use of the PCI Express Gen 2.0 x2 interface, which defines a throughput ceiling that's 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. 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.

Even in mSATA's heyday, though, a replacement was in the works. During development, it was known as NGFF, for "Next-Generation Form Factor." As it took shape, though, it took on its current, final name: M.2. The drives would be smaller, potentially more capacious, and, most important, not necessarily reliant on SATA. The 870 QVO’s write speed comes in at 530MB/s, while the read speed is set at a slightly higher 560MB/s. The write endurance of the SSD is rated at 2,880 TB, much higher than the QLC NVMe SSDs we saw earlier. The high capacity of the 870 QVO and its 2.5-inch form factor makes it the ideal choice for replacing your existing high-capacity hard drives, as the performance gains will be pretty significant than even the fastest ones. We actually like these because often, you often get a robust heat sink on the M.2 drive. Some PCI Express-bus M.2 SSDs can run hot under sustained read/write tasks and throttle their speed. That said, unless you're running a server or something similar, where a drive is constantly getting hammered with reads and writes, that's usually not something you have to worry about. That's because many of these drives are so fast, they get their transfer duties done before they have a chance to get all that hot.Typical SATA drives come in the 2.5-inch form factor similar to hard disks but is way lighter and faster in data transfer. We recommend SATA SSDs if you plan on migrating to a more rapid form of storage from existing hard drives. SATA SSDs are also cheaper than NVMe SSDs, but at 8TB, the difference is not much, so endurance should be the main factor you consider. Final Thoughts I have an Aorus motherboard and wanted to use the second M.2 slot, as the Samsung Evo Plus already installed and the couple of spare slower SATA SSDs were not enough anymore, with a single game taking 100gb easily. In my early career, I worked as an editor of scholarly science books, and as an editor of "Dummies"-style computer guidebooks for Brady Books (now, BradyGames). I'm a lifetime New Yorker, a graduate of New York University's journalism program, and a member of Phi Beta Kappa.