SSD sizes explained
How to decode the strings of numbers used to describe M.2 drives
All of the M.2 drives that we’ve included are 2280 drives, which are the most common type you’ll find, but there are a host of other physical drive sizes out there. So what are the differences? Quite simply, the figures explain the key dimensions of the drive: the first two numbers are the width of the drive in millimetres, and the second number is the length in millimetres.
So, our 2280 drives are 22mm wide and 80mm long. This is the most common size, allowing the most room for memory chips, so capacities tend to be higher at a lower cost. It’s not the only type of SSD, though.
The other common formats are 2260 (60mm long) and 2242 (42mm long), with the even smaller 2230 (30mm long) size starting to become popular. Typically, the smaller formats are used in laptops, where there’s not always space for a “fullsize” SSD.
Cutting down the amount of space on the physical board means that there’s less space for memory chips, so smallersized SSDs tend to have lower capacities. That said, increasing chip density is one of the reasons for the increasing popularity of 2230 drives. You’ll most commonly see them in ultraportable laptops, but we have seen M.2 2230 slots appear in bigger laptops as a way to expand on the supplied storage.
Part of the M.2 configuration is the physical connector. All of the drives we’ve reviewed use the Key M type connector, which
will only work in slots with the female Key M connector. There are different Key types, although M is the most popular.
Typically, most laptops will only take an SSD of one size, so if you’re upgrading, you have to swap like for like, reducing your choice. PCs are different, as motherboards have a movable SSD standoff that can go in different positions.
The standoff can be unscrewed and moved to a new position. The SSD then sits on top of this and is held in place by a retaining screw. While you’ll most likely end up with a 2280 SSD, the PC’s versatility means that you can install a laptop-sized SSD if needed. That can be handy if you have an old laptop that you’re cannibalising for parts, or you simply want to read a laptop SSD on your computer.