What are UHS interface and UHS Speed Class? Category : Specification / Capacity / Performance UHS (Ultra High Speed), the fastest performance category available today, defines bus-interface speeds of up to 312 Megabytes per second. It is exclusively designed for SDHC and SDXC memory cards, and compatible with SDHC and SDXC devices. Is the answer helpful? Related A message pops up on my computer asking me to format my memory card, but I can't execute the format function. Why does Transcend include the Proposition 65 warning? What is SDXC? Technical Support If the answer can't help you, you can contact the Tech Support Department Get Started