USB flash drive

History

First commercial product

Trek Technology and IBM began selling the first USB flash drives commercially in 2000. The Singaporean Trek Technology sold a model under the brand name "ThumbDrive", and IBM marketed the first such drives in North America with its product named the "DiskOnKey" which was developed and manufactured by the Israeli company M-Systems.[citation needed] IBM's USB flash drive became available on December 15, 2000, and had a storage capacity of 8 MB, more than five times the capacity of the then-common floppy disks.

In 2000 Lexar introduced a Compact Flash (CF) card with a USB connection, and a companion card read/writer and USB cable that eliminated the need for a USB hub.

Both Trek Technology and Netac Technology have tried to protect their patent claims. Trek won a Singaporean suit, but a court in the United Kingdom revoked one of Trek's UK patents. While Netac Technology has brought lawsuits against PNY Technologies, Lenovo, aigo, Sony, and Taiwan's Acer and Tai Guen Enterprise Co, most companies that manufacture USB flash drives do so without regard for Trek and Netac's patents.
[edit] Second generation

Modern flash drives have USB 2.0 connectivity. However, they do not currently use the full 480 Mbit/s (60MB/s) which the USB 2.0 Hi-Speed specification supports because of technical limitations inherent in NAND flash. The fastest drives currently available use a dual channel controller, although they still fall considerably short of the transfer rate possible from a current generation hard disk, or the maximum high speed USB throughput.

File transfer speeds vary considerably and should be checked before purchase. Speeds may be given in Mbyte per second, Mbit per second or optical drive multipliers such as "180X" (180 times 150 KiB per second). Typical fast drives claim to read at up to 30 megabytes/s (MB/s) and write at about half that speed. This is about 20 times faster than USB 1.1 "full speed" devices which are limited to a maximum speed of 12 Mbit/s (1.5 MB/s)

References

http://en.wikipedia.org/wiki/USB_flash_drive