The need for speed no longer just applies to cars. Or games related to cars. In an age where digital photography is prevalent, from phones, to cameras, to drones, being able to record and transfer image data at high speeds has become just as important as the camera sensors themselves. That is why the SD Association, the industry group tasked with standardizing SD technology, has announced the latest specification for the tiny data storage. Called, what else, UHS-III, this spec for the SD bus interface doubles the data transfer rates of the previous UHS-II, from 312 MB/s to a whopping 624 MB/s.
To be clear, the SD Association isn’t announcing a new SD card product or a completely new technology. UHS-III is simply a specification that dictates the speed of data transfer between the SD card and a device. Products, specifically SD cards, that meet that specification can proudly display a I, II, or, now, III number beside the SD logo, depending on which spec it complies with.
While SD cards have long been in existence, the UHS bus interface specification is relatively new. The need for standardization came with the arrival of higher capacity SDXC and SDHC cards on the market. In 2010, UHS-I delivered speeds of 104 MB/s, which UHS-II took to 312 MB/s later on. Now with UHS-III, the transfer rate between card and device is guaranteed to be 624 MB/s, the fastest so far in the industry.
UHS-II introduced a second row of pins, the gold bars at the back of the SD card, for the added bandwidth. UHS-III simply makes use of that same row. What this means in practice is there is no need for changing the size or shape of the SD card in order to implement UHS-III. The new spec is also fully backwards compatible, so devices that support UHS-III will still be able to read from and write to older SD cards.
That said, the UHS interface itself is exclusive to SDXC and SDHC only and not for older SD specifications. UHS-III itself will be available for full-sized SD cards as well as microSDHC and microSDXC cards. No new products supporting this new bus interface specification have been announced yet.