A Man In Black/xDtemp

The xD-Picture Card is a flash memory memory card format developed and introduced to the market in July 2002 by Olympus company and Fujifilm, and manufactured by the Toshiba. (Kodak, SanDisk, and Lexar now also sell xD cards.) xD cards are in Olympus and Fujifilm digital cameras, and are available in a range of sizes, from 16 MB to 1 GB. They primarily compete with formats such as Secure Digital Card (SD), CompactFlash (CF), and Sony Memory Sticks. xD stands for extreme digital.

Typically, an xD card is used as storage media for a digital camera, in a form that can easily be removed for access by a Personal computer. A digital camera would use an xD card for storing image files. (As of 2005, xD cards are only used in Olympus and Fujifilm cameras.) With an xD reader (typically a small box that connects via USB or some other serial connection), a user could copy the pictures taken with the digital camera off to his or her computer. Modern computers, both laptops and desktops, generally do not have xD slots even when other memory card slots are available, due to the lesser popularity of the format.

= xD In Comparison =

xD cards sit in between the postage-stamp-sized memory card formats, like Secure Digital Card and Memory Stick Duo, and the micro memory card formats. They are used in a subset of the applications of the older formats, as xD cards are used in digital cameras while the other, older formats are used in digital cameras as well as other devices. On the other hand, they share some characteristics with a newer generation of micro memory card formats, like RS-MMC, miniSD, and MicroSD, which are generally used in high-end cell phones and smartphones.

As the number of installed devices using the older, more-popular formats like CompactFlash, Memory Stick, and Secure Digital Card dwarfs the number of xD-using devices, the economies of scale tend to favor the old guard, making Memory Sticks and SD and CF cards generally cheaper, megabyte for megabyte, than xD cards. Moreover, unlike SD and CF (but much like the Memory Stick), xD as a format is burdened with high costs to license the associated trademarks and patents, driving the cost of xD cards up even further, often double the cost-per-megabyte of a comparable SD card.

xD cards also have lower maximum capacities, an issue that dampens professional and prosumer interest in the format. As of 2005, xD cards are available in sizes up to one gigabyte, whereas Memory Stick Duos go up to two gigabytes, Memory Stick Pros and SD cards go up to 4, and CompactFlash cards up to 8 gigabytes. (This is setting aside the issue of maximum theoretical size, discussed in further detail #Technical Specifications below.)

= Technical Specifications =

The xD card offers a single advantage over its direct competitors: size. An xD card is 20 by 25 by 1.78 millimeter and weighs about 2.8 gram, making it significantly smaller than the matchbook-sized CF card and about half the size of the more-common SD card. As far as size goes, it is much closer to miniSD or RS-MMC, both which are generally used in cell phones rather than digital cameras.

The manufacturer s claimed write speeds for xD-Picture Cards are: for the 16 MB and 32 MB card, 1.3 MB/s. The 64 MB and higher cards achieve 3 MB/s. Both offer a read speed of 5 MB/s. For comparison, CompactFlash memory uses a 150 kB/s baseline, and so a 64 MB xD-Picture Card is equivalent to a 20x CompactFlash card; one limit of CF is 80x, though 40x tends to be marketed to the professional and serious amateur ( prosumer ) user.

A higher-performance, non-backwards-compatible new xD card format known as Type M came out in 2005, and uses Multi Level Cell (MLC) architecture. The 1GB Type M card is called the M1GB (M-XD1GM). Type M will eventually be available in sizes up to 8 GB. The xD Type M cards have a faster standard read rate of 4.0MB/sec and write rate of 2.5MB/sec.

As of , while Memory Stick Pro (Up to 4 GB), SD/MMC (only up to 2 GB), and Compact Flash (Multi-GB) have more, those these large sizes are top of line expensive models, and have a larger form factor. Memory Stick Pro Duo is larger (about the size of SD/MMC) but also only peaks at 1GB.

xD has a lower theoretical capacity then some formats, as well; without a format change, xD cards can scale up to 8 gigabytes, whereas some can go up to 128 gigabytes (in the case of SD and CF) or 32 GB eventually (in the case of the Memory Stick Pro according to Sony). However, both are larger form factors, and Memory Stick Pro cannot be used with a CompactFlash adaptor. The 8 GB max, if not broken, is still higher then a number of other formats including the original Memory Stick (128 MB), Memory Stick Duo (128 MB), Memory Stick Select (2*128 MB), and SmartMedia (128 MB) (and potentially some of the new Micro card formats).

The specification for xD cards (and thus the information needed to implement their use) is tightly controlled by Olympus and Fujifilm. This not so much a disadvantage, but a trait of the current batch of memory cards. Its main competitors, and memory cards in general, are also quite controlled. Memory Stick and its dervatives are tightly managed by Sony for example. Even the more open ones like SD, CF, etc. are controlled by groups which charge for access to the exact standards, or certain technical features.

Some other issues are that some newer Olympus digital cameras disable panoramic mode when an Olympus-branded xD card is not used, and that some older camera s cannot use the new Type M cards without a firmware update or at all. However, xD cards are noted for high-reliablity and are made to certain qualities. So if a third-party card is used, it could cause errors when using the panoramic mode, which is avoided by having the feature disabled alltogether. Also, in general, many old digital cameras cannot take advantage of advances in memory cards, and is not something unique to xD format; the older xD memory cards usable in later cameras too.

=External links=

*[http://www.olympusamerica.com/cpg_section/cpg_xd.asp Olympus America - xD Media] *[http://www.fujifilm.com/JSP/fuji/epartners/PressCenterDetail.jspDBID=NEWS_499702 Fuji press release announcing xD-Picture Card]. *[http://www.xd-picture.com/press/index.html Press Release from XD-Picture about Type M] *[http://www.xd-picture.com/ XD-Picture Card License Office]