With the new speed classes, it's easy to figure out the transfer speed of any SD card.
In 2006, the SD Card Association came out with SD card Speed Classes, a new way of classifying the read/write speed of SD cards. If you know interpret the speed classes, figuring out the read/write speed of a certain memory card is a breeze. This makes choosing a card simpler, as well giving you the assurance that you have the right card for your camera.
Instructions
1. Pick up the SDHC card and turn it so that you can see the front of the card. The back is the blank side with the metal receptors in it, and the front is the side of the card that has any sort of writing or pictures on it.
2. Look near the center of the card. You will see a small number enclosed in the letter "C." This number corresponds with the number of Megabytes that the SDHC card is able to move from one place to another every second, represented by the unit "Megabytes per second," or MB/s. This rate is often called the memory card's transfer speed.
3. Look to see what number is marked on your SDHC Ultra II card. This number represents the Speed Class of the memory card. For example, a symbol with the number "4" enclosed in the letter "C" would mean that your memory card is Class 4. This would also put your card at a minimum transfer speed of 4 MB/s.
Tags: memory card, transfer speed, enclosed letter, number enclosed, number enclosed letter, read write