USB 3.0/3.1/3.2 flash drives
This category brings together flash drives with a USB 3.0, 3.1 or 3.2 interface, because in reality these are three names for one family of standards, even if the newer ones also carry the faster Gen 2 and Gen 2×2 variants. The USB-IF changed the older designations in 2019, so today’s USB 3.2 Gen 1 is the same interface that used to be called USB 3.0. Here you will find drives with a USB-A and a USB-C connector, in metal and plastic housings, and capacities from small ones for documents to large ones for video. The version number on its own says nothing about speed, because on a flash drive it is set mainly by the memory inside.
USB 3.0/3.1/3.2 flash drives
The drives in this category use an interface from the USB 3 family, which has carried three different names over the years. Here you will find classic drives with a USB-A connector, models with USB-C, and swivel or retractable designs without a cap. Capacities run from small drives for documents to large ones for video and backups of entire folders. Right here, though, the version label is more treacherous than on other accessories, so it pays to know what it means.
The USB-IF renamed the whole line twice, in 2013 and again in 2019, so that three names for one speed came about. The original USB 3.0 first became USB 3.1 Gen 1 and finally USB 3.2 Gen 1, without anything changing about the five gigabits per second. A drive marked USB 3.2 can therefore be exactly the same device that was sold years ago as USB 3.0. A higher number on the box means no faster drive on its own; only the Gen 1, Gen 2 or Gen 2×2 suffix settles it.
The real difference comes only from the generation label, and those are three separate speeds. Gen 1 manages five gigabits per second, Gen 2 ten and Gen 2×2 twenty, so there is a factor of four between the extremes. Gen 2×2 sends data over two lanes at once, though, and only the USB-C connector has them. A drive with the classic rectangular USB-A will therefore never reach twenty gigabits, whatever the box says.
On a flash drive the real speed is decided more by the memory inside than by the interface itself. Five gigabits per second works out at 625 megabytes, except that once the encoding overhead is taken off around five hundred is left, and an ordinary Gen 1 drive reads about two hundred megabytes per second anyway and writes sixty to a hundred. Writing tends to be markedly slower than reading, which you notice exactly when you copy a large file to the drive rather than from it. It is therefore worth looking in the description for the figure in megabytes per second and not just for the version number.
Backward compatibility works both ways, so you can plug the drive into an older USB 2.0 port as well. There it drops to four hundred and eighty megabits per second, about a tenth of what Gen 1 can do. The slower of the two always decides, so nothing helps either a fast drive in an old port or a new port with a slow drive.