UHS-III SD card interface capable of 624MB/s bursts announced
(Digital Photography Review)

The SD Card Association has announced the UHS-III standard that allows for maximum data rates twice as fast as the current UHS-II interface. The new interface will allow cards to transfer data at up to 624MB/s and will be used in both SD and Micro SD cards. The UHS-III interface on future devices will be fully backwards compatible with existing SD cards. The cards themselves will include a second row of pins, so will be physically identical to current UHS-II. The adoption of UHS-III branding may cause further confusion with the U3 speed rating that appears on many current cards. This may be mitigated if UHS-III cards prove to be capable of higher guaranteed sustained write speeds, allowing them to wear the `V60` or faster `video speed class` branding announced in 2016. Although an increasing number of cameras (including many recent Fujifilm models, the Olympus E-M1 Mark II and Panasonic GH5) can make full use of the faster maximum transfer speeds of UHS-II cards, we`ve not yet seen any cards that can promise to sustain writing of data at faster than the 30MB/s promised by U3 ratings. This means all the x-hundred megabyte per second write speeds promised on current cards are useful only for bursts of stills: any camera trying to record video at data rates of above 30MB/s (240 mbps) run the risk of stuttering during recording.