Choosing an SSD: fit, capacity, and the specs that matter

Check what your computer accepts

Before comparing prices, check your computer or motherboard documentation for the supported storage connection and physical format. A drive can look right and still use the wrong connection.

M.2 describes the shape and size of a module. It doesn’t establish whether the drive uses SATA or PCIe. NVMe is the storage protocol used by the PCIe SSDs listed here. Match both the interface and the module length: an M.2 2230 drive is 30 mm long, while an M.2 2280 drive is 80 mm long. Check the mounting position and clearance, including any factory heatsink. Kingston explains M.2 formats and interfaces.

A 2.5-inch SATA SSD is another common option. Enterprise formats such as U.2 need appropriate connections too; don’t assume a drive works in your computer because it fits into a bay.

Compare capacity and the offer

Choose enough capacity for the files and applications you expect to keep, then compare both the total price and price per terabyte. The cheapest price per TB can still mean spending more than you need.

Check the exact model number, capacity, condition, and heatsink variant before buying. A bare drive and a factory-heatsink version may have separate part numbers. For used or refurbished drives, read the seller’s warranty and return terms rather than assuming the new-product manufacturer warranty applies.

Read warranty and endurance together

TBW means terabytes written: a manufacturer’s rated amount of writing. Read it alongside the warranty period and the manufacturer’s terms. Samsung, for example, specifies both a time limit and a TBW limit for its 990 PRO. See Samsung’s product specifications.

A TBW rating isn’t a countdown to failure, and it doesn’t tell you how much endurance an individual used drive has left. Whatever you buy, keep a separate backup of files you can’t replace.

Put advertised speed in context

PCIe generation helps identify a drive’s connection capability. Check your system’s support before paying more for a newer generation.

Sequential read and write figures describe advertised maxima. They aren’t a promise that every application or long file transfer will run at that speed. Samsung’s performance notes, for example, explain that its write-cache behavior and transfer size affect the advertised write performance.

Use those figures to understand the broad performance tier. If you regularly write large amounts of data, look for testing of the exact capacity under that workload before paying a premium. Optional details such as TLC or QLC NAND can provide context, but shouldn’t replace checking compatibility, the actual offer, and the warranty.