SD body brands up ultra-high speed cards
SD Cards are to get yet another tiny decal, this time signalling the memory card's ability to handle 104MB/s data transfers.
Actually, it's a bit more than that: the new UHS (Ultra High Speed) symbol also denotes the use of a new card pin-out that's incompatible with the previous one.
Devices that support UHS cards can also take older cards, but clearly you're not going to get the same speed out of them as you will from a UHS card.
Just to confuse matters, the UHS cards will be available in SDHC and SDXC versions - just as the current speed peak, Class 10, is. Class 10 is a minimum write speed of 10MB/s.
SDHC cards use the FAT 32 file system for storage capacities of up to 32GB, while SDXC uses exFAT - FAT 64, effectively - to store up to 2TB of data, as and when such cards arrive in a cost-effective form.
The SD 4.0 specification was developed with a view to raising the write speed to 300MB/s, so the 104MB/s speed is simply the beginning: it's UHS Speed Class 1. ®