Flash drives are often measured by the rate at which they transfer data. Transfer rates may be given in megabytes per second (MB/s), megabits per second (Mbit/s), or in optical drive multipliers such as "180X" (180 times 150 KiB/s).[19] File transfer rates vary considerably among devices. Second generation flash drives have claimed to read at up to 30 MB/s and write at about half that rate, which was about 20 times faster than the theoretical transfer rate achievable by the previous model, USB 1.1, which is limited to 12 Mbit/s (1.5 MB/s) with accounted overhead.[20] The effective transfer rate of a device is significantly affected by the data access pattern.[21]
"Nice device for bulky files....I have 2 of these flash drives and it's more convenient for me to store backups of my most important files on 2 of these flash drives than an external drive because it's easier for me to transfer my data files between 3 devices, carry the drive around in my pocket, and the transfers are easy and fast since it's USB 3.0"