Much like the standard SD memory card, the SDHC (Secure Digital High Capacity or SD 2.0) memory cards are a basic flash digital storage device. The difference is that they allow for capacities above 2.0 GB as well as a variety of speed class ratings.
SDHC memory cards will only work in SDHC-compatible devices and are a relatively new technology, so check your equipment first before you purchase. If you have an older device, it will most likely not work with the Secure Digital High Capacity platform. However, if you own a SDHC-compatible camera, phone, voice recorder, reader, or camcorder - you can use both the updated SDHC format as well as the old SD memory card standard.
There are three SDHC speed classes - Class 2, 4 and 6 and they guarantee data-writing speeds of 2, 4 and 6 MB per second. These speed classes can be extremely important to photographers who need to get a lot of shots in seconds and can't afford to wait for their memory cards to keep up as well as videographers who want to be able to capture lengthy files with a higher quality.
Other benefits also include the ability to easily move large files in the absence of a network, at an acceptable speed and on a medium that's reusable. Unlike recordable DVDs or CD-Rs (including rewritable discs), memory cards have a much longer product longevity up to thousands of cycles and can make data transfer more affordable and sustainable.
Because the Secure Digital High Capacity cards use a different memory storage system and data structure, they will theoretically be able to reach storage capacities of up to 2 terabytes - that's just over two thousand gigabytes. There is one drawback to massive storage capacity in such a small device and that is the risk of physical loss. With the ability to store large amounts, users are less likely to dump their data on a regular basis. Because the cards are so small, they can be easily misplaced or, though it's unlikely, they could malfunction causing a damaging loss of data. Just as it's important to back up your hard drive data, it's crucial to back up your SDHC cards.
Overall, the new Secure Digital High Capacity memory cards are a massive improvement on the SD standard however, they are not compatible with non-SDHC devices, including readers, and their massive storage capacity can increase the impact of a data loss.
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