4 GB SD Memory Cards

High speed SD memory cards are a must have for any digital photographer. It is a well known fact that SD memory cards come in a variety of different sizes but it is less well known that they come in different speeds. As SD memory cards get larger and can hold more information, the time it takes to transfer this information will become longer as such the speed at which your SD memory card can function will become more important.

The SD Association as defined Speed Class Ratings to help ensure manufacturers correctly label their products, which should prevent manufacturers just writing ‘High Speed’ on any memory card they fancy. The three main classes are as followed:

* Class 2: 2 MByte/s – 13x (34.1 mins)
* Class 4: 4 MByte/s – 26x (17 mins)
* Class 6: 6 MByte/s – 40x (11.3 mins)

In brackets is the amount of time it would take to download the entire contents of a 4 GB SD memory card onto a computer via USB connection. As you can see from this data, the time need to download data can vary dramatically and that is why there is such big demand for high speed SD memory cards.

When purchasing a high speed card, make sure that you read the small print closely. Some cards will advertise the maximum speed that can be achieved but it is only possible to achieve these speeds with specific software and/or hardware. It therefore makes more sense to pay close attention t the minimum transfer speed so you at least know the slowest speed you will possibly get.

Panasonic have recently announced research to further devlep the SD memory card with the aim of creating a new high speed SD memory card which will most likely need a new classification. As these memory cards are still in development there is no further detail available.