The full title of the xD card, the xD-Picture Card, gives away its target market, it being squarely aimed at the digital camera market. And if that wasn\’t enough, the fact that it was developed by Fuji and Olympus, two camera firms, gives the game away completely. The xD card is designed to store pictures for safekeeping and to transfer them quickly and easily to a PC or photo-development system (such as an in-store kiosk).
Announced in 2002 the format was intended to take over from SmartMedia cards, which had done an excellent job, but had an in-built 128MB size limit and were physically too large for the smaller cameras beginning to emerge at the beginning of the century. The format was based very closely on that of SmartMedia cards, being just an enclosure around a NAND flash memory chip with an interface very close to that of the chip\’s own pinouts, in the same way that SmartMedia had. This kept manufacture simple and cheap, there being no need for a separate controller as in some other formats, such as Secure Digital SD.
From a marketing point of view, xD has not really delivered in the way that Fuji and Olympus hoped it would. CompactFlash, the venerable format that is a similar size to SmartMedia, has kept its position as the card of choice for high-end professional cameras. This is because camera size in that market segment is such that the larger physical size of the card isn�t a problem, and the bigger capacities that CF offers make a big difference to professional photographers. At the same time, SecureDigital has taken the low-end market for consumer pocket cameras. This has been borne out by the emergence, from 2005 onward, of cameras from Olympus that have xD slots that accept CF cards, and Fuji as of 2007, that take SD cards. This has been welcomed in the camera world as offering customers greater choice, but commercially it must be a sign that the attempt to lock customers into Olympus and Fuji products has failed, and support for the format will fade away, albeit over a long period.
As with all other memory card formats the memory used is solid state, so the information recorded on a card stays there after it’s been removed from a power source. In order to transfer the pictures from a camera to a PC the cards are fitted into a card reader, usually a USB device although occasionally they are built into PCs. The small size of xD cards means that dedicated readers can be very small, and Olympus in fact manufacturer their own, very neat and stylish, xD card reader which is significantly smaller than an ordinary USB flash memory drive (or ‘thumb stick’). Many multi-format card readers will take xD format cards, if not all, although care must be taken with compatibility. There are also many adapters available that will convert an xD card into another format in order to use a different sort of slot, including PC Card (PCMCIA) CompactFlash, and SmartMedia.
Although at the launch Fuji and Olympus announced sizes up to and including 128MB and stated that larger sizes, up to 8MB, would be available the following year, those larger formats turned out to be a lot slower in emerging, with a 1GB card only being launched in 2005. This card was the first of the ‘Type-M’ series cards, which use multi-level cell (MLC) technology to garner the capacity increase, but Type-M cards are much slower at writing data to the card (or, in practical terms, saving your pictures). Later in 2005 yet another new format, ‘Type H’, was announced, which improved write speed but still not to the same level of the original, smaller capacity cards. The upshot of all this is that customers need to know their card types, rather than being able to use any xD card, which hasn’t helped the format win more friends.
| Comparison of Read/Write speeds of the various xD-Picture Card formats | |||
|---|---|---|---|
| Type | Capacity | Write speed
(MBs) |
Read speed
(MBs) |
| Standard | 16 MB, 32 MB | 1.3 | 5 |
| 64 MB, 128 MB, 256 MB, 512 MB | 3 | 5 | |
| M | 256 MB, 512 MB, 1 GB, 2 GB | 2.5 | 4 |
| H | 256 MB, 512 MB, 1 GB, 2 GB | 4 | 5 |
This plethora of different, but physically identical, card formats causes problems as Type-M and Type-H cards won’t necessarily work in some older cameras and card readers. Both Fuji and Olympus have produced compatibility charts on their websites that cover their cameras and card versions, but nothing exists for card readers.
Fuji and Olympus’s strategy appears to have had the opposite effect to that intended. They have kept the format specification very tightly to their chests, which has prevented the mass-market memory manufacturers from using the format and allowing it to spread to other devices such as mobile phones and PDA. CF and Memory Stick format.
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