M.2 Slot

If you opened an older computer, you'd find thick data cables and power cords tangled together. It was a bit like plugging every appliance into the wall with its own bulky plug and cord, until the outlet looked like a spaghetti pile.

The M.2 slot got rid of those clunky cables for parts like storage drives. It's a small connector that sits flat on the motherboard. Slide a thin board, about the size of a stick of gum, in at an angle, tighten one screw, and you're done.

With the cables gone, air flows much better inside the case, so heat is easier to clear out. It also takes up almost no space, which is why it became a key space-saving technology for today's thin, light laptops.

Here's the key thing to remember about M.2: it describes the physical shape of the connector. Two M.2 parts can look identical, yet talk to the computer in completely different ways.

Some M.2 parts use the older SATA road. Others use PCIe (PCI Express), the modern superhighway. An NVMe M.2 SSD, which runs on that highway, reads and writes files several times to over 20 times faster, depending on the generation, than a standard SATA drive.

So before you install an SSD, check your motherboard manual and pick a compatible type. Just because it fits in the slot doesn't mean you'll get top speed.

To be more precise, M.2 comes in several sizes and types. The most common SSDs are labeled "2280," a four-digit number that means 22 millimeters wide and 80 millimeters long.

There's also a "key," which is the position of the notch between the connector pins. A fast SSD usually has the notch on one side of the pins (M-key), while a wireless card usually has it in a different spot (E-key).

Because the notches sit in different places, the wrong kind of part simply won't fit into the wrong slot. Match the length and the notch, and even a beginner can install the right part without a mistake.