A Guide to SDHC
SD cards have become one of the most standard forms of memory cards to be used in digital devices including, Camera’s, PDA’s, Smartphones and MP3 players, replacing the likes of Compact Flash (CF) cards. As technology improves, so do the cards and their capacity. SDHC is the next generation of Secure Digital memory.
What is SDHC?
SD High Capacity (SDHC) card is the new SD memory card based on the SDA 2.00 specification, introduced by the SD Card Association. This new SDA 2.00 specification enables SD cards to reach higher capacities - 4GB-32GB (Currently)*. The theoretical maximum is actually a massive 2048GB!
This improvement in technology means that SDHC works differently compared to the standard SD cards. This new format is not backwards compatible with standard SD format devices.
More SDHC compatible devices are becoming available especially camera and video equipment, whilst PDA’s and Smartphones will most likely have this technology by late 2007 and early 2008.
To ensure compatibility, look for the SDHC logo on cards and host devices.
What is Class Speed Rating?
The SD Association has created and defined 3 speed classes to help you identify speed and performance capabilities/minimum requirements of SD/SDHC cards and the host products.
The SD Speed Class Ratings specify a minimum sustained write speed for SDHC cards.
- Class 2: 2 MB/s
- Class 4: 4 MB/s
- Class 6: 6 MB/s*
You can look for the Speed Class Logo to identify the performance class of your memory cards and host devices.
*1 megabyte (MB) = 1 million bytes; 1 gigabyte (GB) = 1 billion bytes.