Usually, such drives will be custom-stamped with a company's logo, as a form of advertising. The drive may be blank, or preloaded with graphics, documentation, web links, Flash animation or other multimedia, and free or demonstration software. Some preloaded drives are read-only, while others are configured with both read-only and user-writable segments. Such dual-partition drives are more expensive.[61]
USB 2.0 flash drives have a transfer rate of up to 480Mbps, while USB 3.0 flash drives allow for transfer rates 10 times faster — up to 4.8Gbps. However, you can only take advantage of this higher speed if your device has a USB 3.0 port. Although USB 3.0 flash drives and other devices are backwards compatible with USB 2.0 ports, they will only operate at a USB 2.0 rate.
Floppy disk drives are rarely fitted to modern computers and are obsolete for normal purposes, although internal and external drives can be fitted if required. Floppy disks may be the method of choice for transferring data to and from very old computers without USB or booting from floppy disks, and so they are sometimes used to change the firmware on, for example, BIOS chips. Devices with removable storage like older Yamaha music keyboards are also dependent on floppy disks, which require computers to process them. Newer devices are built with USB flash drive support.
A drawback to the small size of flash drives is that they are easily misplaced or otherwise lost. This is a particular problem if they contain sensitive data (see data security). As a consequence, some manufacturers have added encryption hardware to their drives, although software encryption systems which can be used in conjunction with any mass storage medium will achieve the same result. Most drives can be attached to keychains or lanyards. The USB plug is usually retractable or fitted with a removable protective cap.
Like all flash memory devices, flash drives can sustain only a limited number of write and erase cycles before the drive fails.[71][unreliable source?][72] This should be a consideration when using a flash drive to run application software or an operating system. To address this, as well as space limitations, some developers have produced special versions of operating systems (such as Linux in Live USB)[73] or commonplace applications (such as Mozilla Firefox) designed to run from flash drives. These are typically optimized for size and configured to place temporary or intermediate files in the computer's main RAM rather than store them temporarily on the flash drive.
