While pen drives can be an easy way to transfer files between computers, they can also be a vector for malware infections. Any computer with autoplay turned on may auto-execute infected files on a pen drive, triggering an infection. Pen drives also have a relatively short lifespan compared to other forms of media, as each cell of the flash memory can only accept a set number of rewrites.
Pen drives can also be limited by PC hardware. The speed at which files can be read or written depends on the version of USB installed in any given PC. USB 2.0 can transfer around 60 megabytes per second, which can make transferring large files a tedious task. USB 3.0, on the other hand, can reach speeds of up to 640 megabytes per second. However, very few pen drives are able to reach this maximum speed limit, forcing users to pay close attention to specifications in order to get the fastest pen drive possible.
Pen drives are also prone to hardware failure. The interior of a pen drive is often simply a circuit board soldered to the USB plug, and since these devices stick out of the side or front of a computer, they tend to get bumped or struck very easily. The junction point is the weakest spot and a failure point, making it easy to break the USB connection and render the drive useless.