secure digital exended capacity (SDXC)
With the SDXC card, which stands for Secure Digital Extended Capacity, the SD Association( SDA) has established a standard for memory cards with storage capacities of up to several terabytes.
A standard SD card has storage capacities of up to 2 GB, while the Secure Digital Card High Capacity( SDHC) has storage capacities of up to 32 GB. Higher storage capacities from 64 GB up to 2 TB are offered by SDXC cards.
The write speeds are divided into speed classes of 2, 4, 6, 8 and 10 MB/s. To ensure that the enormous storage capacity of the SDXC card can be accessed, it is equipped with a UHS bus on which data rates of 104 MB/s and 312 MB/s are realized. The UHS bus increases the write speeds to 10 MB/s and 30 MB/s, provided that the UHS concept is supported by both devices. As a file system, the SDXC card no longer uses FAT32, but Extended File Allocation Table( exFAT) with a 64-bit address space.
The SDXC card is also available in a smaller form as a microSDXC card with dimensions of 11 x 15 mm. It was developed especially for small handy devices and has a storage capacity of 32 GB in contrast to the SDXC card. The microSDXC card have the same shape and size as the microSD card, with which it is backwards compatible.