Wednesday, March 28, 2012

What is XD-Picture Card ?

XD card, full name XD picture Card, is developed specially for saving digital pictures. It becomes popular because of its mini size, light and convenient features. XD card has a super large capacity and great compatibility. It can be used with various card readers and connected to PC.

XD-PICTURE CARD, XD card in short, which is taken from "Extreme Digital", is a new kind of Flash Memory card. Compared to other Flash Memory, it has lots of advantages. The size of it is 20*25*1.7mm, and the total volume is only 0.85 cubic centimeter. It weighs only about 2g. It is the lighter and smaller digital Flash Memory ay present. The theoretical maximum capacity can be 8GB. The common capacity of XD card is 512MB, 1G, and 2G. XD card uses single side 18 pins port. Fuji and Olympus have developed XD card with the largest capacity of 1GB in 2004. And the read-write speed is faster (reading rate is 5MB/S, and writing rate is 3MB/S). It satisfies large amount of data write-in and has a lower consumption. XD-picture card can not only be used at PC adaptor card and USB card reader, but also Compact Flash convert adaptor. It also can be used as a storage medium of Compact Flash in DC. Although it is a little expensive, with the decreasing price of Flash Memory chips and card, the price of XD card is going to decrease, too.

XD card is developed by Japanese Olympus and Fuji together. It is a new kind of storage card. It has a compact appearance. The size is only 20*25*1.7mm and it weighs only 2g.

The precautions of XD card:
(1) Try not to format XD card through a card reader; otherwise it will cause the format error of the card. This will make the card cannot save pictures and drop dead halt.
(2) When transmit pictures through a card reader, it is better to copy than to cut. If there is need to delete a picture, it is suggested to delete it on the DC rather than on the computer.
The common kinds of XD card in the market are these three kinds: normal type, M type, and H type.

The sizes of these three kinds are the same. The different point is the different technology and chips, so that the speed is different, too.
The earliest XD card is the so-called normal type. The normal reading rate is 5M/S and write-in rate 3M/S.
M type is the MLC technology XD card developed in 2005. It is produced for decreasing the price. However it runs into the trouble of incompatibility with some old Olympus and Fuji devices. And because of the low speed (the most terrible disadvantage of MLC), it often makes troubles when recording videos. The normal reading rate is 4M/S and write-in rate 2.5M/S.
H type, is short for HIGH-SPEED. The read-write speed is twice faster than normal type, and three times than M type. It is worthy of the name HIGH-SPEED. At this field Fuji and Olympus have separately choosed different technology to meet the speed requirement. The H type of Olympus uses the DC main control in a fixed firing way to promote the speed. The H type of Fuji uses different digital code to promote the speed (there is H type of Fuji which uses Olympus' technology, and it may be the Olympus OEM).   

You need to pay attention to that no matter H type or M type; it is only compatible with cretin devices. Make sure before you buy it.
Write in: 9M JEPD Fine: 1.6 fps 4 pieces

15.0 sec (SanDisk Ultra II CF)
~9.8 sec (512 normal XD)
9.0 sec (1G XD type-H)
Write in: 9M RAW 1 piece
~11.9 sec (SanDisk Ultra II CF)
~7.8 sec (512 normal XD)
6 – 6.5 sec (1G XD type- H)
It looks not as exaggerating as the advertisement

When using a XD card of Olympus, the way of taking out the pictures from the DC to the computer is "cut". And when plugging the card back to the DC there will be some operator messages like "format" or the power will be turned off. 

Actually XD card has this kind of disadvantage. It often loses pictures or card disabled when using a card reader. It is not very possible to repair the card so use the USB line to read the pictures on the computer.  

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