04-02-2008 08:04 AM
SD cards were originally only designed for capacities up to 1GB. Changes were made to the specification which allowed capacities of 2GB to be realized. But, in order for a device to be able to use a 2GB SD card, the device must be designed to address the memory space. Unfortunately, not every device is able to do this, and there is no easy way to tell if the device is compatible without first calling the manufacturer of the device.
If a 2GB card is put into a device that only supports 1GB, the host device may ask to format the card and repartition it to 1GB.
So, for example, I insert a 2GB SD card into a built-in card reader on a computer that is 4 years old. When I attempt to access it, a need to format message may appear, and if I were to format the card and then check the capacity, it will read somewhere around 980 MB, instead of the 1.9 GB that I was expecting.
This will happen with any host device that is not compatible with 2GB cards; it can be a mobile phone, built in card reader, GPS unit, etc.
It is always best to contact the manufacturer of your device to find out if it is compatible with a specific capacity SD card.
If a card has been repartitioned to 1GB, it may be “fixed” by using a 3rd Party repartition tool. Windows can not repartition USB Removable Disks in Disk Management. A good program to use is the free HP USB Disk Storage Format Tool. If you do an internet search for this tool you will find places to download it.
In order for a device to use the new SD High Capacity cards the host controller in the device must be SD Specification 2 compliant. This means that the camera (or any device that uses a SD card) must have been designed to use SD cards in capacities higher than 2GB. Usually you will see the SDHC logo printed on the device or in the user guide.
If you are not sure, contact the manufacturer of the device and inquire as to whether their product is SDHC compatible.
This not only applies to full size SDHC cards, but also miniSDHC and microSDHC cards, too.