While for most of the storage cards we use, we call them as SD cards, and you might not even notice about the card’s type until you read the terms such as SDHC and SDXC on the card. They are different, and although not a huge difference, you should know about the card while purchasing one.
SD (Secure Digital) is a standard for memory cards, to be used in cameras, smartphones, and any gadget that needs external storage. SD was the only type earlier, and it was widely used but there were certain limitations that made the SD Association to look forward and come up with higher standards, when the SDHC was introduced with the limit of 32GB, but you know that at the current advancements, even 32GB isn’t enough as a storage in the card. Thus came in, the SDXC standard. Although the current SDXC cards have up to 128GB capacity, the limit set for SDXC cards is 2TB.
The first difference between the three – capacity. As said above, 2GB was for SD, 32GB for SDHC, and 2TB for SDXC.
The next difference between the three storage card types – Read and write speed. The newer cards have a faster read and write speed, and to compare, the SDHC cards had a maximum speed of 12.5Mbps, while the SDXC cards could reach the speeds of 104Mbps. Thus, the use case changes, and while SDHC cards can be used in smartphones and digital cameras, the SDXC ones are preferred in video cameras and camcorders.
The third difference is with the type of formatting. As the SDXC cards use a new type of formatting, it won’t be recognized in older hosts. The SD card uses FAT16 format, SDHC cards use FAT32 format, while the SDXC cards use exFAT format.
The fourth and another important difference is with the size of the cards – While you can get a SDHC card in three different sizes, i.e. standard, mini, and micro, the SDXC cards are currently available only in standard size, and there is no mini or microSDXC card available.
The standards come with backward compatibility, thus if you have a device that supports SDHC card, it would support SD card as well. Similarly, if there is a SDXC card supporting device, there will be support for both SDHC and SD card.
Choosing one among these is not easy, because while you know all the advantages of the SDXC card over the other two types, the pricing is a factor you need to consider and if someone is looking to purchase a very basic card just for a secondary storage in their phone, then there is no need to pay the extra amount to get the SDHC card.
On the other side, if you are looking to have a good storage for your video camera, compromising and getting a SDHC won’t make sense, because the camera might upgrade later but the card won’t be able to handle the heavy video jobs in the new one.