XD-Picture Card
xD-Picture Card is a format of flash memory data storage device developed and introduced to the market in July 2002 by Olympus and Fuji, and manufactured by the Toshiba Corporation. xD cards are designed for the digital photography market, and are an alternative to and competitor of formats such as Compact Flash (CF), Sony Memory Sticks, and Microdrives.
The competitive advantages of the xD-Picture Card are its very small form factor, having measurements of 20 by 25 by 1.78 mm and a weight of about 2.8 g; and claimed low power consumption. (By comparison, the CF1 is 43 by 36 by 3.3 mm, and the CFII is 43 by 36 by 5 mm.)
xD-Picture Cards are available in a range of sizes, from 16 MB to 512 MB, and with a theoretical limit of 8 GB.
Manufacturers claimed write speeds for xD-Picture Cards are: for the 16 MB and 32 MB card, 1.3 MB/s. The 64M B and higher cards achieve 3 MB/s. Both offer a read speed of 5 MB/s. By comparison, Compact Flash memory uses a 150 kB/s baseline, and so a 64 MB xD-Picture Card is equivalent to a 20x Compact Flash card; the current limit of CF is 80x, though 40x tends to be marketed to the professional and serious amateur user.
PCMCIA and CF adapters are available for xD-Picture cards, enabling them to be used in readers and cameras which do not have native support for the xD format.
Fuji's marketing department note that the name "xD-Picture Card" was inspired by the phrase "eXtreme Digital".