I like the Universal Serial Bus. I remember all too well the round 5-pin AT keyboard connector, the weird bus mouse interface that connected my Microsoft Mouse to an ISA card, the RS-232 serial port for my modem, and the huge parallel port for my printer. Nowdays, these all plug in to identical USB ports. Life should be merry.
However, when USB 2.0 came out, the marketers went crazy. First, the simple technical background. In USB 1.x, devices could run at either Low speed, 1.5 Mbit/s, or Full speed, 12 MBit/s. The big advance of USB 2.0 was to add a new Hi speed(sic) of 480 Mbit/s.
You might think it sensible that USB 2.0 should refer to devices that run at this new super fast speed. Indeed, often the only reference to speed given in product advertising for items such as printers or USB flash drives is "USB 2.0 compatible", or just "USB 2.0". Unfortunately, in a bewilderingly anti-consumer decision, a device of any speed that has been recently certified as USB compliant can be labelled USB 2.0. Indeed, peripheral manufacturers have taken full advantage of this. For example, an old USB 1.1 scanner might now be called USB 2.0, enticing customers to purchase this "faster" version.
Thus, the USB 2.0 label on a peripheral means absolutely nothing. Instead, we have to remember to counterintuitive fact that, in the land of USB, Hi speed is faster that Full speed.
PS. I wrote this entry because I've been looking to purchase a USB flash drive, and the online shops label many of them as USB 2.0, but don't give any indication as to their actual speed. Sometimes even the manufacturers withhold this information from their web sites. When this happens, it's safest to assume the worst.