What is the difference between SD and SDHC and SDXC cards?

sd card

What is the difference between SD and SDHC and SDXC cards? SD card, SDHC card, SDXC card differ in specifications, SD card supports up to 2GB and the minimum capacity is 128mb SD card and 256mb SD card, SDHC supports up to 32GB, SDXC supports up to 2TB (2048GB), and digital devices that support SDXC cards are compatible with SD card and SDHC card. If the device only supports SDHC cards, then this device cannot use SDXC cards, but it is compatible with SD cards. If the device only supports SD card, it is not compatible with SDXC, SDHC card. It is backwards compatibility and also called downward compatibility. For these three types of cards, we will explain in details, what are their functions and features?

SD card

SD was an earlier version and is said to have evolved from MMC. Maximum capacity supports for 2GB only, also 2gb SD card bulk is popular for sales.

The SD memory card is one small storage medium jointly developed by Panasonic, Toshiba, and SanDisk in 1999. The size of the SD card is equivalent to the size of a stamp, and the weight is very light, only 2g, but its transmission speed and storage capacity is very high, and the security is very high, also it is very convenient to carry. A global boom has been triggered since it is launched.

When the of SD memory cards had been introduced to the market, meanwhile the Secure Digital Card Association (SDA) was established to develop relevant specifications and to promote the promotion of SD memory cards. After years of development, SD card has become the world’s most popular electronic card format for mobile phones; it is suitable for mobile phones, digital cameras (DSC), MP3 music players, personal computers and other electronic products.

SDHC card

SDHC is one large-capacity SD card, also known as SD High Capacity, which supports a maximum capacity of 32GB.

SDHC, the full name of which is Secure Digital High Capacity, SDHC’s biggest feature is high capacity (2GB-32GB). In addition, the SD Association stipulates that the SDHC must use the FAT32 file system. This is because the FAT16 file system previously used in the SD card supports a maximum capacity of 2 GB and does not meet the SDHC requirements.

As the successor to the SD card, SDHC’s main feature is the file format, which has been upgraded from the previous FAT and FAT16 to FAT32, and raised the capacity to 32GB. At the same time, the transmission speed is redefined as Class2, Class4, Class6, etc. This high-speed SD card can support real-time storage of high-resolution video recording.

The SDHC card has the same external dimensions as the current SD card, and the copyright protection function is the same as before. However, since the file system has been changed, the SD device that only supports the FAT12/16 format has been incompatible. The machine can support FAT 32, which also can read the existing SD card in FAT12/16 format.

All SD cards that is larger than 2G must comply with the SDHC specification. The specification states that the SDHC must meet at least Class 2 speed grades and must have an SDHC logo and speed grade flag on the card.

SDXC card

SDXC (SD eXtended Capacity) is one new standard released in 2009, supporting a maximum capacity of 2TB.

SDXC is the abbreviation of SD eXtended Capacity. It is one new standard. In addition to the capacity can support a maximum of 2TB, it can support a transmission speed of 300M/s, that is fully a “high-speed SD” card. However, there are not many digital cameras that support SDXC cards, mainly new products introduced this year, and SDXC is not backward compatible. It does not support ordinary SD and SDHC card slots and card readers.

For most digital cameras and SLRs, high-speed SDHC memory cards are fast enough for high-speed continuous shooting and high-definition video capture.

Through the understanding of SD, SDHC and SDXC, when choosing to purchase SD card, you can choose the appropriate specifications according to your needs, also you need to choose reliable memory card wholesaler. These memory cards are now growing faster with more capacity. If you understand the difference among them in advance, so that some problems can be avoided in time. In addition, the main function of the memory card is to store data, and you should pay attention to backing up the data during use to avoid data loss.