The SD Association has announced a new speed class for SDHC and SDXC memory cards to help consumers select the most appropriate cards for different applications.

 

June 24, 2010: The SD Association has announced a new speed class for SDHC and SDXC memory cards to help consumers select the most appropriate cards for different applications.
The new Ultra High Speed (UHS) class is designed for the UHS-I bus interface, the fastest performance category available today. It delivers four times the data transfer speed of the former fastest cards, which supported 25 Megabits/second transfer. With transfer speeds of 104Mbps, they are ideal for recording large HD-quality video clips with pro-sumer camcorders and DSLRs and also recording real-time high-definition broadcasts.
The latest developments mean there are now four speed classes, with differing applications. They are outlined in the table below.

Speed Class

Bus interface

Card types

Applications

Standard

Normal Bus

SD, miniSD, microSD, SDHC, miniSDHC, microSDHC, SDXC, miniSDXC, microSDXC

SD video recording

HD and Full HD video recording

High-speed Bus

Full HD video recording, HD stills bursts

UHS-1

UHS Bus

SDHC UHS-1, SDXC-UHS-1

Extended HD video and broadcasts recording

The new UHS-1 class appears to have been developed to enable SD cards to be used as a primary recording format in professional and pro-sumer video camcorders. Details can be found at www.sdcard.org/developers/tech/speed_class.